OK. The deal is this. For some reason, the save to .pdf option that was causing the crash was when it was set to print from certain pages (not all), but only when the first page was something other than page one.
So after rewriting the script and a couple of more layouts, it works again!
It sounds like this may have been related to a known issue in FileMaker Pro 10 where saving records to PDF could crash if the starting page number was not 1 and the layout extended beyond one page. We are currently looking into this issue.-TSDivaFileMaker, Inc.