There has been a problem for many years that most of us have come across developing for Internet Explorer with background images "flickering" when the cursor is hovering over them. (here's an example). This is due to to Internet Explorer checking for a new version of the background image declared in the background-image css attribute when the mouse hovers over the tag. The flicker issue may also be accompanied with the hourglass flicking on or even no image flicker, but the hourglass flickers!
/*@if (@_jscript_version >= 4)
document.execCommand("BackgroundImageCache", false, true);
Essentially, if you include this script somewhere in your page (best towards the top) then it will resolve this problem. Banzai!
I can't take credit for this solution - MisterPixel came up with the goods looking into DHTML behaviours in IE with regards to another problem (a bit like Fleming discovering penicillin!).