A neat little solution for the image flash that I found:
<meta http-equiv="Page-Enter" content="blendTrans(Duration=0.1)">
Put that in the head of your document. Apparently, Internet Explorer has some kind of “fade in/fade out” option for pages that slows down the deletion of the cache (something IE loves to do, and the above tag prevents the flickering image effect from happening by exploiting this feature.
Keep in mind, with images, it always helps to have the smallest filesize possible to help avoid the “flashing image” issue. The smaller the filesize, the faster it loads.