I use a hover function like this which works fine when using external image sources http://jsfiddle.net/Fftfv/5/
var paper = new Raphael("game-frame",600,600);
obj = paper.image("http://upload.wikimedia.org/wikipedia/commons/thumb/6/63/French_suits.svg/300px-French_suits.svg.png", 100, 100, 300, 300).hover(function () {
this.toFront();
this.animate({ transform: 's1.6'}, 50, 'linear');
},function() {
this.animate({ transform: 's1'}, 50, 'linear');
});
The problem is i take my images from my site so my img source looks like "images/a5.png" in this case chrome requests the image every time something is done to it like hover. In firefox this works fine as it uses the already loaded image.