IF you create a brand new file and create a brand new script (don't import it) with these steps, do you still get a crash?
Well, just got Mountain Lion downloaded and installed on one of my Mac & test ran the program and it works fine! I'm going to experiment more & see if I can figure out what's going on before I open my big mouth again (should have done that BEFORE posting.....!). This user is in an office 3 hours away, so it's more difficult to "physically" get hold of his computer...
Thanks for the answer - I WILL try you suggestion, but the problem may not be with the file or FMP..!