Image flicker in IE6

This is due to IE 6 keeps check for the background image specified in css property everty time the element is moved over. Note that IE 5 or IE 7 do not have this problem.

A good post about this problem is at http://www.mister-pixel.com/

The solution is to add following javascript code inside the HEAD of the page:
try {
document.execCommand("BackgroundImageCache", false, true);
} catch(err) {}

This fix works only with Internet Explorer 6, Service Pack 1 or newer.
Also, the fix does not apply if you change the background image on :hover. It only prevents the flicker of the same background image, when changing other rules inside the :hover state. But you can still change the background position.