I was running an Iphone 3g 4.0.1 for over a year with no problems, then sat I woke up to the itunes logo.

I futzed around and ended up installing the 4.2.1 custom ipsw and the ipad baseband.

I managed to get it working, but then about 1/2 of the time when it went to sleep, it wouldn't wake up and the only way to get it back was to hold the home and sleep button until it reset.

I tried downgrading to 4.1 and activating with a SIM from AT&T - same thing.

If I hit the sleep button sometimes it comes back, sometimes it doesn't. I have no idea? Has anyone else had this problem. It never did this until I upgraded to 4.2.1 and changed the baseband.