Music shifts, or mysteriously replaced by other music

FCP 7
MacPro 2.16 GHz Intel Core 2 Duo
3 GB 6677 DDR2 SDRAM
10.6.8

This has been happening once in a while for the past few weeks and has never happened before that. I lay down a music track, save it, and at some point either it is replaced with another piece of music in my Browser, or what was the beginning of the piece is now the middle of the piece. I can't figure this out. Today one music clip I laid in played perfectly, then I worked on another part of the timeline, came back to that music piece and the first ten seconds was a compeltely different tune then the music was fine; just the beginning was altered. It does not happen all the time, but just when I think I have a large segment done with four or five music pieces laid in, then play the timeline, one of the pieces is shifted as described. Any ideas?

1- make sure you're not using mp3s, 2- reconnect media / re-render

as far as im aware it's just something fcp can do on occasion, also make sure you're using wavs/aiffs, all of one or the other (although i've even had it happen with wavs)

when this happened to me it was because the music had been rendered,
and there was some mix-up with the render files.

solution was to trash the render files and re-render.


nick