For the last couple of weeks, my S3 has been freezing sometimes when I try to unlock it (I use the Face Unlock feature). It's not the same reaction every time; sometimes I get past the unlock screen, but the widgets take forever to load ... then the screen goes black (but the status bar is visible) and then returns to the lock screen. Other times, it freezes on my Face Unlock image; other times, it doesn't recognize my face and kicks me to the PIN login screen, then freezes there. Sometimes it freezes on multiple images -- ghosted, so that the PIN screen is frozen on top of the Face Lock image. I can't turn it off when it freezes or goes to black; sometimes it unfreezes and goes back to the lock screen, while other times it goes to the Verizon screen. Eventually it returns to the lock screen.
Pulling the battery doesn't fix it; it's just as likely to freeze and crash after a battery pull as before one. I've tried booting into CWM and clearing cache and dalvik cache, but that doesn't help, either.
This morning, it woke up fine, but froze when I got in the car and tried to turn on bluetooth. From that point on, over the next 30 minutes, it froze and/or crashed 20 times. The 21st time, it suddenly decided to play nice and has been working fine ever since.
I'm rooted (using the updated VZW stock image), on Android 4.0.4, no ROMs yet, running Nova Launcher Prime. Used TiBu to freeze a lot of bloatware; I run Juice Defender, Lux, Screebl, and AdAway. Is there a way to find out what's causing the freezing and crashing?