I put my PC to hibernate as usual, but this time it threw a BSOD after hanging for 10min. I fired it back up in the morning and it crashed several times before Windows became usable.
Attached are a bunch of minidumps with the same power state failure. The most recent dumps on 8/31/12 (today) and 8/19/12 have ntoskrnl.exe+7f1c0 as the cause. The other two dumps (from 2011) have ntoskrnl.exe+7cc40, one of them being INTERNAL_POWER_ERROR.