Hi, I have a strange issue with my 2012 Mini. Once in a few boots, usually every 1-2 days, instead of loading the system immediately, the Mini ends up in the startup manager. All partitions are there but I need to select the sys partition manually to continue. All works fine afterwards, no Startup Manager during the next boot up either. I have tried resetting the NVRAM and SMC without success, the issue keeps returning. The mini is running OS X 10.10.1 off a Samsung 850 Pro SSD. Any ideas?