The safest way to minimise the crashes related to new Usertrack (and the word 'new' is the important part of that sentence!):

1. Use NO OTHER AUDIO FILES on the first song you apply a Usertrack to, not even Realtracks!
2. It's best to do a throwaway 8 bar "initiation" song for the first generation of a new Usertrack, and have any other tracks as midi only instruments for its first generation.
3. After this has been done successfully at least once, you should be safe to use the UT as any other Realtrack, but the most safe way still for future uses is to generate any other track first and freeze them, and then add the Usertrack last into the song.


The primary cause for these crashes - which the above instruction is attempting to minimise - appears to be due to how BBox must create additional .bt files to go with the Usetrack files the first time you generate the track (which is why 'new' is key word here and explains why the pre-existing Accordion worked fine). Something in this process seems to be very straining on the program, so if it also has to generate other Realtracks and/or waste precious horsepower on additional audio tracks = BOOM!.

Solution, until a proper fix is found - avoid straining the program.

Just because you can, doesn't mean you should!
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BBox 2022 Audiophile, Mac Pro Intel, OSX 10.6.8, 800x600 (TV VGA)