On imported video clips, audio gradually lags more and more. On longer clips, the effect becomes greater, even after chopping the clip into smaller pieces. Unless I'm importing clips only a couple of minutes at a time, the effect renders video unusable.
Movie Edit Pro 15, 8.0.5.8
Windows 7 Home Premium, 64-Bit
I have no idea if I have the right answer for you - I just noticed your question after posting mine. I am new to this myself, and am getting ready to edit my home videos, a lot of which is Hi8 analogue from my old camcorder. I use a BlackMagic Intensity Pro video capture card. If I capture to my server (hard disks) the audio will go out of sync. The only way I can keep it in sync is to capture to the SSD on my desktop. So for me the sync problem is totally related to the write data rate of the storage location. Maybe this is something you could check?