Hi Jeffrey,
Sorry for just getting to this now. Regarding why the behavior changes with the SPI clock, I'm not really sure. I think you have give the MSP430 guys a shout. Regardless, I don't expect it to hang during a SPI transfer. Did you guys carry out the tests I asked earlier? Dunk said it worked well when only one task ran therefore it's probably something happening in the other tasks that affects it. Let's try to narrow it down.
Thanks,
Moses