Unfortunately I can only offer another hinky situation. We have a project running on Dual Core Xeon processors running Windows 7 (64) w/ 10 GB of ram and a project that was started in CS3 is now suffering a lot of lag during playback.
We have run into dropouts of audio as well when recording out to tape. The timeline keeps on going with no sign of error, but on review of the tape, there are definitely audio anomalies. The worst part is trying to recreate the problem is nearly impossible. Gremlins are definitely running amuck.
Any help would be greatly appreciated.