for an unknown reason i can't seem to get open-e to boot via pendrive, which is why we used an IDE DOM (the system boots but halts at around 20%), to be honest it didn't really matter to us which way it booted

and again, no not everynight, just seems to occur between say 02:00 and 05:00, non of our other systems seem to have issues with power etc... + the UPS isn't firing any warning so i don't think its that.