Thanksgiving day I had my phone on but was doing things around the house and when I went to check my phone it wouldn't wake. Holding down the power button, nothing, it was dead. I know the battery wasn't drained. So I plugged it into my USB and the light didn't turn on either. I sat staring at the phone for a few seconds to troubleshoot and it suddenly began to boot up and after everything loaded I could confirm it was half charged.
I'm running the same version of Cyanogen as you. Are you using the original battery or 3rd party? Mine is 3rd party.
Have you had other strange occurrences leading up to this? Twice in a week I woke up to find my phone on even though I know I shut it down the night before and not accidentally rebooted.
Since I was able to get my phone to boot back from temporary dead the phone has frozen twice while texting. I didn't battery pull or anything, it just rebooted by itself after a few minutes. I plan on switching back to my old battery to see what happens.