diff --git a/jquery.sketchable.js b/jquery.sketchable.js
index 3c71ebb..057f1e6 100644
--- a/jquery.sketchable.js
+++ b/jquery.sketchable.js
@@ -161,9 +161,9 @@
           elem.unbind("mouseup", mouseupHandler);
           elem.unbind("mousemove", mousemoveHandler);
           elem.unbind("mousedown", mousedownHandler);
-          elem.unbind("touchstart", touchHandler);
-          elem.unbind("touchmove", touchHandler);
-          elem.unbind("touchend", touchHandler);
+          elem.unbind("touchstart", touchdownHandler);
+          elem.unbind("touchmove", touchmoveHandler);
+          elem.unbind("touchend", touchupHandler);
         }
         elem.removeData(_ns);
 
diff --git a/jquery.sketchable.memento.js b/jquery.sketchable.memento.js
index d134460..3218583 100644
--- a/jquery.sketchable.memento.js
+++ b/jquery.sketchable.memento.js
@@ -3,14 +3,14 @@
  */
 /**
  * @name $
- * @class 
- * See <a href="http://jquery.com/">the jQuery library</a> for full details.  
+ * @class
+ * See <a href="http://jquery.com/">the jQuery library</a> for full details.
  * This just documents the method that is added to jQuery by this plugin.
  */
 /**
  * @name $.fn
- * @class 
- * See <a href="http://jquery.com/">the jQuery library</a> for full details.  
+ * @class
+ * See <a href="http://jquery.com/">the jQuery library</a> for full details.
  * This just documents the method that is added to jQuery by this plugin.
  */
 ;(function($) {
@@ -23,12 +23,12 @@
    * var mc = new MementoCanvas( $('canvas-selector') );
    */
   var MementoCanvas = function($canvas) {
-    
+
     // Private stuff //////////////////////////////////////////////////////////
     var stack = [];
     var stpos = -1;
     var self  = this;
-    
+
     function prev() {
       if (stpos > 0) {
         stpos--;
@@ -59,8 +59,8 @@
         data.sketch.graphics.drawImage(snapshot, 0,0);
       });
     };
-    
-    // Key event manager. 
+
+    // Key event manager.
     // Undo: "Ctrl + Z"
     // Redo: "Ctrl + Y" or "Ctrl + Shift + Z"
     // TODO: decouple shortcut definition, perhaps via jquery.hotkeys plugin.
@@ -79,10 +79,10 @@
         }
       }
     };
-    
+
     // Public stuff ///////////////////////////////////////////////////////////
-    
-    /** 
+
+    /**
      * Goes back to the last saved state, if available.
      * @name undo
      * @memberOf MementoCanvas
@@ -90,10 +90,11 @@
     this.undo = function() {
       prev();
       $canvas.sketchable('handler', function(elem, data) {
-        data.strokes = stack[stpos].strokes.slice();
+        if (stack[stpos])
+          data.strokes = stack[stpos].strokes.slice();
       });
     };
-    /** 
+    /**
      * Goes forward to the last saved state, if available.
      * @name redo
      * @memberOf MementoCanvas
@@ -101,10 +102,11 @@
     this.redo = function() {
       next();
       $canvas.sketchable('handler', function(elem, data) {
-        data.strokes = stack[stpos].strokes.slice();
+        if (stack[stpos])
+          data.strokes = stack[stpos].strokes.slice();
       });
     };
-    /** 
+    /**
      * Resets stack.
      * @name reset
      * @memberOf MementoCanvas
@@ -113,7 +115,7 @@
       stack = [];
       stpos = -1;
     };
-    /** 
+    /**
      * Save state.
      * @name save
      * @memberOf MementoCanvas
@@ -125,7 +127,7 @@
         stack.push({ image: elem[0].toDataURL(), strokes: data.strokes.slice() });
       });
     };
-    /** 
+    /**
      * Init instance.
      * @name init
      * @memberOf MementoCanvas
@@ -135,7 +137,7 @@
       $(document).off("keypress", keyManager);
       $(document).on("keypress", keyManager);
     };
-    /** 
+    /**
      * Destroy instance.
      * @name destroy
      * @memberOf MementoCanvas
@@ -144,19 +146,19 @@
       $(document).off("keypress", keyManager);
       this.reset();
     };
-    
+
   };
-  
+
   // Bind plugin extension ////////////////////////////////////////////////////
-  
+
   var plugin = $.fn.sketchable;
   var availMethods = plugin('methods');
-  
+
   function configure(elem, opts) {
     var self = elem, options = $.extend(true, plugin.defaults, opts);
     // Actually this plugin is singleton, so exit early.
     if (!options.interactive) return opts;
-    
+
     var mc = new MementoCanvas(elem);
     var callbacks = {
       init: function(elem, data) {
@@ -171,7 +173,7 @@
         data.memento.destroy();
       }
     };
-    
+
     // A helper function to override user-defined event listeners.
     function override(ev) {
       if (options && options.events && typeof options.events[ev] === 'function') {
@@ -196,7 +198,7 @@
       }
       plugin.isMementoReady = true;
     }
-    
+
     // Expose public API for jquery.sketchable plugin.
     $.extend(availMethods, {
       undo: function() {
@@ -206,13 +208,13 @@
         mc.redo();
       }
     });
-    
+
     return plugin.defaults;
   };
-  
-  /** 
+
+  /**
    * Creates a new memento-capable jQuery.sketchable object.
-   * @param {String|Object} method name of the method to invoke, 
+   * @param {String|Object} method name of the method to invoke,
    *  or a configuration object.
    * @return jQuery
    * @class
@@ -225,5 +227,5 @@
     var conf = configure(this, opts);
     return initfn.call(this, conf);
   };
-  
+
 })(jQuery);
diff --git a/jquery.sketchable.memento.min.js b/jquery.sketchable.memento.min.js
index fd74865..f774995 100644
--- a/jquery.sketchable.memento.min.js
+++ b/jquery.sketchable.memento.min.js
@@ -1,4 +1 @@
-/*!
- * Memento plugin for jQuery sketchable | v1.1 | Luis A. Leiva | MIT license
- */
-(function(e){var a=function(m){var h=[];var g=-1;var i=this;function l(){if(g>0){g--;var o=new Image();o.src=h[g].image;o.onload=function(){j(this)}}}function k(){if(g<h.length-1){g++;var o=new Image();o.src=h[g].image;o.onload=function(){j(this)}}}function j(o){m.sketchable("handler",function(p,q){q.sketch.clear();q.sketch.graphics.drawImage(o,0,0)})}function n(o){if(o.ctrlKey){switch(o.which){case 26:if(o.shiftKey){i.redo()}else{i.undo()}break;case 25:i.redo();break;default:break}}}this.undo=function(){l();m.sketchable("handler",function(o,p){p.strokes=h[g].strokes.slice()})};this.redo=function(){k();m.sketchable("handler",function(o,p){p.strokes=h[g].strokes.slice()})};this.reset=function(){h=[];g=-1};this.save=function(){g++;if(g<h.length){h.length=g}m.sketchable("handler",function(o,p){h.push({image:o[0].toDataURL(),strokes:p.strokes.slice()})})};this.init=function(){e(document).off("keypress",n);e(document).on("keypress",n)};this.destroy=function(){e(document).off("keypress",n);this.reset()}};var d=e.fn.sketchable;var f=d("methods");function c(j,g){var o=j,p=e.extend(true,d.defaults,g);if(!p.interactive){return g}var m=new a(j);var l={init:function(i,q){q.memento=m;q.memento.save();q.memento.init()},mouseup:function(i,q,r){q.memento.save()},destroy:function(i,q){q.memento.destroy()}};function h(q){if(p&&p.events&&typeof p.events[q]==="function"){var i=p.events[q];p.events[q]=function(){var r=Array.prototype.slice.call(arguments,0);i.apply(o,r);l[q].apply(o,r)}}else{d.defaults.events[q]=l[q]}}if(!d.isMementoReady){var n="init mouseup destroy".split(" ");for(var k=0;k<n.length;k++){h(n[k])}d.isMementoReady=true}e.extend(f,{undo:function(){m.undo()},redo:function(){m.redo()}});return d.defaults}var b=f.init;f.init=function(h){var g=c(this,h);return b.call(this,g)}})(jQuery);
\ No newline at end of file
+(function($){var MementoCanvas=function($canvas){var stack=[];var stpos=-1;var self=this;function prev(){if(stpos>0){stpos--;var snapshot=new Image;snapshot.src=stack[stpos].image;snapshot.onload=function(){restore(this)}}}function next(){if(stpos<stack.length-1){stpos++;var snapshot=new Image;snapshot.src=stack[stpos].image;snapshot.onload=function(){restore(this)}}}function restore(snapshot){$canvas.sketchable("handler",function(elem,data){data.sketch.clear();data.sketch.graphics.drawImage(snapshot,0,0)})}function keyManager(e){if(e.ctrlKey){switch(e.which){case 26:if(e.shiftKey)self.redo();else self.undo();break;case 25:self.redo();break;default:break}}}this.undo=function(){prev();$canvas.sketchable("handler",function(elem,data){if(stack[stpos])data.strokes=stack[stpos].strokes.slice()})};this.redo=function(){next();$canvas.sketchable("handler",function(elem,data){if(stack[stpos])data.strokes=stack[stpos].strokes.slice()})};this.reset=function(){stack=[];stpos=-1};this.save=function(){stpos++;if(stpos<stack.length)stack.length=stpos;$canvas.sketchable("handler",function(elem,data){stack.push({image:elem[0].toDataURL(),strokes:data.strokes.slice()})})};this.init=function(){$(document).off("keypress",keyManager);$(document).on("keypress",keyManager)};this.destroy=function(){$(document).off("keypress",keyManager);this.reset()}};var plugin=$.fn.sketchable;var availMethods=plugin("methods");function configure(elem,opts){var self=elem,options=$.extend(true,plugin.defaults,opts);if(!options.interactive)return opts;var mc=new MementoCanvas(elem);var callbacks={init:function(elem,data){data.memento=mc;data.memento.save();data.memento.init()},mouseup:function(elem,data,e){data.memento.save()},destroy:function(elem,data){data.memento.destroy()}};function override(ev){if(options&&options.events&&typeof options.events[ev]==="function"){var fn=options.events[ev];options.events[ev]=function(){var args=Array.prototype.slice.call(arguments,0);fn.apply(self,args);callbacks[ev].apply(self,args)}}else{plugin.defaults.events[ev]=callbacks[ev]}}if(!plugin.isMementoReady){var events="init mouseup destroy".split(" ");for(var i=0;i<events.length;i++){override(events[i])}plugin.isMementoReady=true}$.extend(availMethods,{undo:function(){mc.undo()},redo:function(){mc.redo()}});return plugin.defaults}var initfn=availMethods.init;availMethods.init=function(opts){var conf=configure(this,opts);return initfn.call(this,conf)}})(jQuery);
diff --git a/jquery.sketchable.min.js b/jquery.sketchable.min.js
index 870bfd7..08903c6 100644
--- a/jquery.sketchable.min.js
+++ b/jquery.sketchable.min.js
@@ -1 +1 @@
-(function($){var _ns="sketchable";var methods={init:function(opts){var options=$.extend(true,{},$.fn.sketchable.defaults,opts||{});return this.each(function(){var elem=$(this),data=elem.data(_ns);if(!data){if(options.interactive){elem.bind("mousedown",mousedownHandler);elem.bind("mousemove",mousemoveHandler);elem.bind("mouseup",mouseupHandler);elem.bind("touchstart",touchdownHandler);elem.bind("touchmove",touchmoveHandler);elem.bind("touchend",touchupHandler);this.onselectstart=function(){return false}}}var sketch=new jSketch(this,options.graphics);sketch.isDrawing=false;elem.data(_ns,{strokes:[],coords:{},timestamp:(new Date).getTime(),sketch:sketch,options:options});if(typeof options.events.init==="function"){options.events.init(elem,elem.data(_ns))}})},strokes:function(arr){if(arr){return this.each(function(){var elem=$(this),data=elem.data(_ns);data.strokes=arr})}else{var data=$(this).data(_ns);return data.strokes}},handler:function(callback){return this.each(function(){var elem=$(this),data=elem.data(_ns);callback(elem,data)})},clear:function(){return this.each(function(){var elem=$(this),data=elem.data(_ns)||{},options=data.options;if(data.sketch){data.sketch.clear();data.strokes=[];data.coords={}}if(options&&typeof options.events.clear==="function"){options.events.clear(elem,data)}})},reset:function(opts){return this.each(function(){var elem=$(this),data=elem.data(_ns)||{},options=data.options;elem.sketchable("destroy").sketchable(opts);if(options&&typeof options.events.reset==="function"){options.events.reset(elem,data)}})},destroy:function(){return this.each(function(){var elem=$(this),data=elem.data(_ns)||{},options=data.options;if(options.interactive){elem.unbind("mouseup",mouseupHandler);elem.unbind("mousemove",mousemoveHandler);elem.unbind("mousedown",mousedownHandler);elem.unbind("touchstart",touchHandler);elem.unbind("touchmove",touchHandler);elem.unbind("touchend",touchHandler)}elem.removeData(_ns);if(options&&typeof options.events.destroy==="function"){options.events.destroy(elem,data)}})}};$.fn.sketchable=function(method){if("methods functions hooks".split(" ").indexOf(method)>-1){return methods}else if(methods[method]){return methods[method].apply(this,Array.prototype.slice.call(arguments,1))}else if(typeof method==="object"||!method){return methods.init.apply(this,arguments)}else{$.error("Method "+method+' does not exist. See jQuery.sketchable("methods").')}return this};$.fn.sketchable.defaults={interactive:true,mouseupMovements:false,relTimestamps:false,multitouch:true,events:{},graphics:{firstPointSize:3,lineWidth:3,strokeStyle:"#F0F",fillStyle:"#F0F",lineCap:"round",lineJoin:"round",miterLimit:10}};function getMousePos(e){var elem=$(e.target),pos=elem.offset();return{x:Math.round(e.pageX-pos.left),y:Math.round(e.pageY-pos.top)}}function saveMousePos(idx,data,pt){if(!data.coords[idx]){data.coords[idx]=[]}var time=(new Date).getTime();if(data.options.relTimestamps){if(data.strokes.length===0&&data.coords[idx].length===0)data.timestamp=time;time-=data.timestamp}data.coords[idx].push([pt.x,pt.y,time,+data.sketch.isDrawing])}function mousedownHandler(e){if(e.originalEvent.touches)return false;downHandler(e)}function mousemoveHandler(e){if(e.originalEvent.touches)return false;moveHandler(e)}function mouseupHandler(e){if(e.originalEvent.touches)return false;upHandler(e)}function touchdownHandler(e){var elem=$(e.target),data=elem.data(_ns),options=data.options;var touches=e.originalEvent.changedTouches;if(options.multitouch){for(var i=0;i<touches.length;i++){var touch=touches[i];downHandler(touch)}}else{downHandler(touches[0])}e.preventDefault()}function touchmoveHandler(e){var elem=$(e.target),data=elem.data(_ns),options=data.options;var touches=e.originalEvent.changedTouches;if(options.multitouch){for(var i=0;i<touches.length;i++){var touch=touches[i];moveHandler(touch)}}else{moveHandler(touches[0])}e.preventDefault()}function touchupHandler(e){var elem=$(e.target),data=elem.data(_ns),options=data.options;var touches=e.originalEvent.changedTouches;if(options.multitouch){for(var i=0;i<touches.length;i++){var touch=touches[i];upHandler(touch)}}else{upHandler(touches[0])}e.preventDefault()}function downHandler(e){if(e.which===3)return false;var idx=e.identifier||0;var elem=$(e.target),data=elem.data(_ns),options=data.options;data.sketch.isDrawing=true;var p=getMousePos(e);if(options.graphics.firstPointSize>0){data.sketch.fillCircle(p.x,p.y,options.graphics.firstPointSize)}if(!data.coords[idx]){data.coords[idx]=[]}if(data.coords[idx].length>0){data.strokes.push(data.coords[idx]);data.coords[idx]=[]}saveMousePos(idx,data,p);if(typeof options.events.mousedown==="function"){options.events.mousedown(elem,data,e)}}function moveHandler(e){var idx=e.identifier||0;var elem=$(e.target),data=elem.data(_ns),options=data.options;if((!options.mouseupMovements||data.strokes.length===0)&&!data.sketch.isDrawing)return;var p=getMousePos(e);if(data.sketch.isDrawing){var last=data.coords[idx][data.coords[idx].length-1];data.sketch.beginPath().line(last[0],last[1],p.x,p.y).stroke().closePath()}saveMousePos(idx,data,p);if(typeof options.events.mousemove==="function"){options.events.mousemove(elem,data,e)}}function upHandler(e){var idx=e.identifier||0;var elem=$(e.target),data=elem.data(_ns),options=data.options;data.sketch.isDrawing=false;data.strokes.push(data.coords[idx]);data.coords[idx]=[];if(typeof options.events.mouseup==="function"){options.events.mouseup(elem,data,e)}}})(jQuery);
+(function($){var _ns="sketchable";var methods={init:function(opts){var options=$.extend(true,{},$.fn.sketchable.defaults,opts||{});return this.each(function(){var elem=$(this),data=elem.data(_ns);if(!data){if(options.interactive){elem.bind("mousedown",mousedownHandler);elem.bind("mousemove",mousemoveHandler);elem.bind("mouseup",mouseupHandler);elem.bind("touchstart",touchdownHandler);elem.bind("touchmove",touchmoveHandler);elem.bind("touchend",touchupHandler);this.onselectstart=function(){return false}}}var sketch=new jSketch(this,options.graphics);sketch.isDrawing=false;elem.data(_ns,{strokes:[],coords:{},timestamp:(new Date).getTime(),sketch:sketch,options:options});if(typeof options.events.init==="function"){options.events.init(elem,elem.data(_ns))}})},strokes:function(arr){if(arr){return this.each(function(){var elem=$(this),data=elem.data(_ns);data.strokes=arr})}else{var data=$(this).data(_ns);return data.strokes}},handler:function(callback){return this.each(function(){var elem=$(this),data=elem.data(_ns);callback(elem,data)})},clear:function(){return this.each(function(){var elem=$(this),data=elem.data(_ns)||{},options=data.options;if(data.sketch){data.sketch.clear();data.strokes=[];data.coords={}}if(options&&typeof options.events.clear==="function"){options.events.clear(elem,data)}})},reset:function(opts){return this.each(function(){var elem=$(this),data=elem.data(_ns)||{},options=data.options;elem.sketchable("destroy").sketchable(opts);if(options&&typeof options.events.reset==="function"){options.events.reset(elem,data)}})},destroy:function(){return this.each(function(){var elem=$(this),data=elem.data(_ns)||{},options=data.options;if(options.interactive){elem.unbind("mouseup",mouseupHandler);elem.unbind("mousemove",mousemoveHandler);elem.unbind("mousedown",mousedownHandler);elem.unbind("touchstart",touchdownHandler);elem.unbind("touchmove",touchmoveHandler);elem.unbind("touchend",touchupHandler)}elem.removeData(_ns);if(options&&typeof options.events.destroy==="function"){options.events.destroy(elem,data)}})}};$.fn.sketchable=function(method){if("methods functions hooks".split(" ").indexOf(method)>-1){return methods}else if(methods[method]){return methods[method].apply(this,Array.prototype.slice.call(arguments,1))}else if(typeof method==="object"||!method){return methods.init.apply(this,arguments)}else{$.error("Method "+method+' does not exist. See jQuery.sketchable("methods").')}return this};$.fn.sketchable.defaults={interactive:true,mouseupMovements:false,relTimestamps:false,multitouch:true,events:{},graphics:{firstPointSize:3,lineWidth:3,strokeStyle:"#F0F",fillStyle:"#F0F",lineCap:"round",lineJoin:"round",miterLimit:10}};function getMousePos(e){var elem=$(e.target),pos=elem.offset();return{x:Math.round(e.pageX-pos.left),y:Math.round(e.pageY-pos.top)}}function saveMousePos(idx,data,pt){if(!data.coords[idx]){data.coords[idx]=[]}var time=(new Date).getTime();if(data.options.relTimestamps){if(data.strokes.length===0&&data.coords[idx].length===0)data.timestamp=time;time-=data.timestamp}data.coords[idx].push([pt.x,pt.y,time,+data.sketch.isDrawing])}function mousedownHandler(e){if(e.originalEvent.touches)return false;downHandler(e)}function mousemoveHandler(e){if(e.originalEvent.touches)return false;moveHandler(e)}function mouseupHandler(e){if(e.originalEvent.touches)return false;upHandler(e)}function touchdownHandler(e){var elem=$(e.target),data=elem.data(_ns),options=data.options;var touches=e.originalEvent.changedTouches;if(options.multitouch){for(var i=0;i<touches.length;i++){var touch=touches[i];downHandler(touch)}}else{downHandler(touches[0])}e.preventDefault()}function touchmoveHandler(e){var elem=$(e.target),data=elem.data(_ns),options=data.options;var touches=e.originalEvent.changedTouches;if(options.multitouch){for(var i=0;i<touches.length;i++){var touch=touches[i];moveHandler(touch)}}else{moveHandler(touches[0])}e.preventDefault()}function touchupHandler(e){var elem=$(e.target),data=elem.data(_ns),options=data.options;var touches=e.originalEvent.changedTouches;if(options.multitouch){for(var i=0;i<touches.length;i++){var touch=touches[i];upHandler(touch)}}else{upHandler(touches[0])}e.preventDefault()}function downHandler(e){if(e.which===3)return false;var idx=e.identifier||0;var elem=$(e.target),data=elem.data(_ns),options=data.options;data.sketch.isDrawing=true;var p=getMousePos(e);if(options.graphics.firstPointSize>0){data.sketch.fillCircle(p.x,p.y,options.graphics.firstPointSize)}if(!data.coords[idx]){data.coords[idx]=[]}if(data.coords[idx].length>0){data.strokes.push(data.coords[idx]);data.coords[idx]=[]}saveMousePos(idx,data,p);if(typeof options.events.mousedown==="function"){options.events.mousedown(elem,data,e)}}function moveHandler(e){var idx=e.identifier||0;var elem=$(e.target),data=elem.data(_ns),options=data.options;if((!options.mouseupMovements||data.strokes.length===0)&&!data.sketch.isDrawing)return;var p=getMousePos(e);if(data.sketch.isDrawing){var last=data.coords[idx][data.coords[idx].length-1];data.sketch.beginPath().line(last[0],last[1],p.x,p.y).stroke().closePath()}saveMousePos(idx,data,p);if(typeof options.events.mousemove==="function"){options.events.mousemove(elem,data,e)}}function upHandler(e){var idx=e.identifier||0;var elem=$(e.target),data=elem.data(_ns),options=data.options;data.sketch.isDrawing=false;data.strokes.push(data.coords[idx]);data.coords[idx]=[];if(typeof options.events.mouseup==="function"){options.events.mouseup(elem,data,e)}}})(jQuery);