I hardly ever see a random reboot, and when I do I feel like it was Facebook doing it.
I just had a lock up, and in this case (and it's happened like this a few times now,,,) you can really imagine it's a CPU problem. The phone becomes oddly slow. Not in that everything is taking ages to load or swap to, but scrolling mostly. I was trying to browse this thread, and I stopped being able to flick down to make it scroll quickly. Instead I had to drag down and it would slowly scroll the page at the same rate as the finger. After posting my last message on here, I locked the phone via the power button, and then wanted to check the time. Pressing the power button did nothing (as normal in the lock ups) After leaving the phone for 10 minutes, it was still locked up ad i had to 10sec long press and restart the phone. It's really frustrating!