Image Flicker Problem
IE has an interesting bug, which causes images to reload from server each time a mouseover event is triggered. There are several clientside ways around this problem they are described here: http://www.fivesevensix.com/studies/ie6flicker/
But the real working solution is to change .htaccess on the webserver. Here is what needs to be done: http://dean.edwards.name/my/flicker.html