Safari and jquery animation performance

[Limenote]

Hi guys, can anyone tell me why safari gives such a poor frame rate with jquery animation compared to other browers?

 

[Limenote]

So its the actual rendering of the effects as opposed to any poor coding? im using jquery to perform a few div transformations and some jpeg opacity changes, its very simple code for example my facebook button:

$("#facebookbutton").hover(
	function(){$("#facebookbutton").stop().animate({backgroundColor: "#006cff", height: 50},{duration:200, easing:"easeOutCirc"} );},
	function(){$("#facebookbutton").stop().animate({backgroundColor: "#000", height: 36}, {duration:1000, easing:"easeInOutElastic"});}
	);

I cant seem to find a good explanation on google (sorry if its obvious).