There could be a number of causes, but this will happen when a new OC profile or setting is applied to the CPU.  I mention this because in particular if you touch anything in the OC tab of AWCC, and then push the tabs back to where they were before closing out, it will apply a custom setting on your CPU.  That causes the double start you describe the next time the PC restarts.  Sort of a glitch in the program IMHO.
This just started happening about a week ago...everything seems to be working ok ...just this odd new behaviour when turning on the computer.  any ideas what causes this is or maybe a symptom of something starting to fail?  or is there some bios setting that got turned on?
Aurora R9, powers on, then off, then on and boots up