iTunes audio/video drifts out-of-sync
I have for a while been having problems with watching videos I have downloaded from the iTunes Store on my PC. I'm running windows 7, all my drivers are up to date, and the videos play fine if I open them up in Quicktime. If I watch them in iTunes, however, the audio and video get out of sync rather rapidly... If I watch a show in iTunes, I need to pause and restart it every 30 seconds or so, otherwise it just becomes too annoying to watch. Clicking pause then play again syncs it back up, but again it doesn't last long. I open the files in Quicktime and they play just fine, and considering iTunes just uses Quicktime for video playback, the problem must be with iTunes. I have gone through several iTunes updates, hoping with each one that the problem gets fixed, but it never does... can anyone help me??