A significant amount of ATI users have taken to the AMD user to user forums to complain about grey screens, crashes and colored-striped hangups.
(There's actually countless forums out there with threads like this – including at least 4 threads in our own forums. I'm concentrating on the AMD forums because these guys, between them, have collected nearly 40 pages of possible causes involving everything from Windows, to mobos, to RAM.)
So far it's unclear as to what is causing the problem. Users report that grey, brown or colored stripes/screen appear while playing games, watching movies and in some cases, while idle. The problems seems to be confined to the HD 5xxx series, although there are a couple of mentions of 4xxx cards
after huge amounts of forum trawling, we're seeing the following model numbers crop up again and again: 4770, 4850, 4870, 5770, 5850 and 5870. The cards seem to be coming from all different companies; the following are the ones we've seen crop up more than a few times from different users: XFX, Sapphire, Diamond, ASUS and HIS.