I just bought a Powercolor hd5770 and it's working great, except I sometimes go blackscreen on Starcraft 2 for about 20 seconds, and it tells me something along the lines of "My driver experienced a problem and stopped responding, but was recovered".
As soon as I popped in the card the first time, I went and googled the driver, and I wound up with ATI Catalyst version 2010.0302.2233.40412.
Did I do something wrong? It seems to me that getting the latest driver would prevent me from running into issues. I'm on Vista 32bit btw.