Could be. What kind of video card do you have? Could be the drivers for that...well could be anything, but that would be the first thing I'd check if it's a driver issue. Can you check the event log? See anything out of the ordinary in there?
When you flashed the bios, did you go through, have it reset all values to default, exit, then go back in to make changes? All the bios flashes I've done recommended doing this. Perhaps you didn't change one of the settings back and that's the problem. Personally I set all bios cacheable settings to none (as far as caching the bios or video, of course leave the cpu cache enabled), set pnp os to no, and disable anything I don't need (such as onboard audio if I have a separate sound card).