It sounds like it's a bad file on your sdcard. I would copy your sdcard to your pc and do a wipe of data, cache, boot and system. Then format your sdcard. Install a fresh ROM and see how it goes. Then you can add back only the files you need (music, pics, backups) from the files you copied over to your pc.
Rom: Codename Android 1.0.1
Kernel: Imo's Lean Minimalistic Experimental
Went back to stock and still had issues. So far looks like Advanced Task Killer is solving my problems. The verizon guy suggested it, I never needed it before, but the phone has been behaving, since I installed it.
Task killer has not fixed anything. Went to VZW store today, and they are shipping me a new phone. She said because the screen his heat sensitive it may act like someone is touching it when no one is. I am not sure about the logic, but I am looking forward to a new phone.
did the new phone solve your problem, i noticed my phone keeps freezing only if i have the sd card in it, tried formatting on phone and pc, but as long as i have all my music and pics on it it freezes, when its blank it doesnt freeze, vzw sent me a new phone but it did the same thing too.