VirtualDub unable to keep audio sync'd on *source* audio

[falconne]

I've got a rather unusual problem in VirtualDub (1.6.14) that started happening recently. I've edited many videos in it without problems, but all of a sudden run into the problem where if I edit any vido to cut out bits (e.g. commercials) and save the avi with "Direct Stream Copy" for both audio and video, the audio in the resulting video will drift out of sync as the movie plays.

All the settings in VirtualDub are at their defaults. I know I could play with frame rate adjustments to get the audio to sync, but for the test case described above, I shouldn't have to, as I'm not bringing in a new audio stream. I've tried with several avi files now, basically opening it in VirtualDub, cutting out just 3 minutes or so from the middle, setting both video and audio streams to "Direct Stream Copy" and saving a new avi. In all cases, the audio is well out of sync by the end of the avi.

In fact, if I load up any avi, set video to "full processing" and use a different codec and reencode a new avi, even that video will have audio drift. So it seems any kind of processing within VirtualDub screws it up.

I haven't knowingly installed any new audio or video drivers recently and as I mentioned, I've edited plenty of videos using that installation VirtualDub before. Can anyone think of a reason I'm getting these problems?

Thanks.

[Bjs]

Have to ask .

Are you doing this preview part in vdub ?

If yes , use any other play back program to preview video clips .

Example : "the audio is well out of sync by the end of the avi"

Preview mode in vdub , it happens .