I purchased my 5850 in mid-January and its been decent outside of the gray screens (which has been fixed as of 10.2). But now, I'd say 1 out of 5 boots my computer will boot up with lines/artifacts everywhere in this bios/post screen and I'll have to press my reset button and it'll boot up without a problem.
Once it's booted up I have no problems playing games for long sessions, benchmarking, etc. It's just the boot.
Any ideas on what might be causing this with no problems in "real world" use?
My specs are i7 920, Gigabyte EX58-UD5, 6GB 3x2 G.Skill 1600MHz, Sapphire HD 5850, and an Antec EarthWatts 650. Everything is running at stock.
Well, the whole grey screen thing has been a bit of a mystery to me. I never got any with my 5850, so I don't know what originally caused them. It could be that your card actually was/is slightly unstable, and that is causing the trouble.