I have a strange screen problem with default UAC settings (and it often appears, to a lesser degree, during boot) Black (or white) streaks, missing or broken lines when the desktop is dimmed to show a system message. If, in UAC, I choose "Don't Dim Desktop"... the problem goes away when messages appear. The regular desktop is fine. This only happens when the boot screens are shown, and when the UAC is allowed to dim the desktop. I have an ASRock 4CoreDual SATA2, eVGA 7600GS on AGP (sorry, can't go to PCIe right now,) 2GB of ram. This happened under both the Win 7 Beta and RC1, which I'm running now. Any thoughts?