jerky fading with scaled images in firefox and ie

jerky fading with scaled images in firefox and ie

I'm building a simple image gallery, and I was having problems with the cross-fade effect between images I'd created being jerky in Firefox and Internet Explorer (Chrome and Safari were fine).

I thought my technique using jQuery's fade might be at fault, so I switched to the jQuery Cycle Lite plugin, but the same problems happened.

I've just discovered the issue. I'm using JS to dynamically scale the images to fill the viewport - just by setting the width and height of the img. It seems that if I remove this scaling, the fading is smooth.

Has anyone encountered this problem? Any idea how to have smooth fading with scaled images in FF and IE?