Honestly, I'd probably ignore it. The built in 'monitors' are not to be used for quality control anyway. They're only purpose is to let you see the content, which apparently you can. Always use a properly calibrated external TV for QC.
But it's quite annoying though. I'm having the same problem and I'm trying to sync audio with video. I'm always worried that it won't sync up right. Is there really no solution to this?
Sync is a different issue entirely.
I must apologize, I must've read the issue wrong. My issue is that the video playback is choppy. When I had Vista Home Premium, CS4 PPro video playback was quite smooth. But now that I'm on Win 7 Pro, the playback looks like it's lagging.
I'm on a quadcore computer, 4gb of ram, 512 mb nVidia video card. I believe all my drivers are updated.