This happened to me two days ago on my G1 and hasn't stopped:
Whenever I press the camera button on my phone it reboots the phone immediately. Whenever I try to open the Snap Photo app it also reboots my phone immediately.
So I assumed it was a software problem, so I followed the youtube videos to unlock and update your phone to the new cupcake version:
I followed the two Jailbreak to update to RC33 version videos, then proceeded to do the Cupcake 1.5 update video (by JesusFreak).
The phone was successfully updated and everything worked. SO I went to try the VideoCamera application that comes with the Cupcake Update. I pressed the Videocamera button and it RESET MY PHONE AGAIN!?
I googled it and didn't find any answers for this problem. Does anyone here know what is going on and how to fix this?