Black screens are usually related to GPU overheating issues. I found the stock van settings for AMD/ATI cards to be somewhat lacking and focusing mainly on noise level instead of system stability. I don't want to cook my card thank you very much ATI! I fixed the trouble with black screens I had a long time ago with Neverwinter Nights 2 by manually setting fan speeds with MSI Afterburner.

http://i41.tinypic.com/ranoug.jpg


Those above are the fan speed settings I use with my overclocked HD 5850.