The following information is New Vegas related not FO3: I wasn't able to use any type of auto saving (vanilla, casm, etc.) until I inserted a PCB after each save then bam the crashes I had been experiencing while fast traveling and/or moving through load doors went away. I thought about tossing a menu into my personal auto-saver (it PCBs after each save obviously) and uploading it, but I just don't feel like messing with it, however I felt I should share this information in case it's of use to anyone else. Edit: I also found that the file that does the auto-saving has to be an .esm and not an .esp, or I still get a few ctds. Weird...