Strange Sync Problem w/tracks

I am using Ntrack on a laptop with a Lexicon Omega. Generally it works very well. However, my band was playing a live show outside this weekend and I brought the laptop to record the performance.

I connected the lexicon as usual (USB) to the computer and took 4 subgroups out of the mixing board, one into each lexicon input. At the beginning of each set, I started the recording, and stopped it at the end of the set. This created essentially one long set (40 minutes or so) of 4 tracks to mix.

When listening to the songs later some are fine, but some appear to have one track out of sync. So for example, the recordings are fine for the first 4 songs and part of the way into song 5 the vocals go out of sync with the rest of the recorded tracks which still appear to be fine. It is not a gradual thing, it just suddenly changes. I have recorded several individual songs before, but none 40 minutes long. I believe I have seen this before some time ago on one track, but I don’t recall the circumstances.

Any help or suggestions would be greatly appreciated.

Thanks in advance

You can probably salvage what you have using the “how do I transfer from 4-track tape” topic in the FAQ.

As for why you had the sync problem in the first place, well that could be many things, none of which I can think of right now…