Here's a video I took to demonstrate it: ARHAsfhsf002.flv video by Flare_shadow - Photobucket (Note, the mouse is held down from the 3 second to 7 second mark... the point at which the photoshop window flashes and acts like I've let go of the mouse is the point at which the thing happens)...
Nah, it's just plain old Photoshop 7. It's not just photoshop that it happens to -I've noticed it tends to happen with programs that use a lot of memory like firefox and WMP.
I have a bit of an odd query, and I'm not quite sure how to describe it properly but I shall try my best. Often when I'm running a program, the icon in the taskbar will disappear and very quickly reappear (as if 'refreshing' itself probably the best way I can think of to describe it). Usually...