I have an 20" iMac G5 Rev. A. Since I installed Leopard a few months ago, it's given me some major video problems, especially after a cold start. When I first start it up, I notice some red pixels in the default Leopard screen background. The dock and menu bars act strange, with icons disappearing and reappearing, and when I went to start Safari it looked like the attached screenshot. The logic board was replaced a couple of years ago for the VRAM problem that the Rev. A iMacs had, so I don't think it's a hardware issue. This looks similar to the video problems people were experiencing with some Mac Pros, but I couldn't find any report of this happening on an older, pre-Intel iMac. Has anyone else had this problem or found a fix?