I tried copying the file back from my DAP (a Sansa e200 v1) back to the PC and it skipped briefly at the same point, although foobar2000 did go on to play the rest of the song. I've just tried recopying the original ripped FLAC and the file seems to play OK now, but I don't think this is the first time this has happened for me - any ideas on what could be causing the problem?