I still have this issue on one miner. I've tried different SDCards, different firmware (including Debian Desk from a forum user), I have even swapped out the RaspPi. Still have the same issue where cgminer fails with a segmentation fault. I see this by invoking cgminer from the command line.

What I'm trialling now is running just one module at a time. I unplugged the PCIe cable from every module except the first one, and it ran fine on one module for 24 hours. Power down, try the same with just module 2... and so on. I run each for at least 24 hours as a test. Still working through this. Then I'll try two modules... then three etc until I can run stable with as many as possible.