After being annoyed with my previous ROM, I thought I'd install ICS on my SGS2 (until CM9 comes out). But, sadly, it now reboots several times a day without any real reason. The device is just lying there on the table doing nothing and every now and then the screen turns on and I can watch it reboot.

So, how would I start to analyse this issue? Obviously I could try to flash different ROMs like a mad man until the issue resolves itself, but I would prefer a more sensible approach.