I found this when translating rockminers site:
1 ambient temperature is too high lead (above 37 degrees), please try to keep around the mining machine ventilation.
2. SD card is faulty, by re-programming the mirror or replace the SD card solved.
3 with a USB data cable shorted lead to instability, check whether the USB cable OK.
nr. 1 is definitely not a problem, And if the sd card is corrupted should it not be not mining at all?
Has anyone succesfully ran it on a windows pc with cgminer? (can you use a stock cgminer 4.5.0 (which supports r-box) or do you need their fork?) because then i could use cgwatcher to reboot when no shares are accepted or perhaps identify if the problem is in the miner itself or in the pi.....
That isn't true about the SD card corruption, sectors can have errors and it partially work. You can try running with 1 module for a while and see if you still get restarts. Monitor the temps before a restart.