[lkillen]

Pull the SDCard and reboot and run for awhile and see if the problem persists. If it goes away, back-up your card and reformat it. There is a chance that the phone is accessing the card and getting hung up.

The things that cause a phone to "hang" or any program for that matter are a bad written app. It is amazing how many endless loops find themselves into the world. Access violations where a program steps into memory it does not own. Tasks that lack proper timeouts. Timeouts are defensive code to abandon a task when the desired resutls are not being accomplished. Task lock concurrency (thread lock). "I will meet you at the corner but if I get there first, I will mark an X on the sidewalk. If you get here first, be sure to erase my X".
And of course, it could be degrading hardward but it is usually logic.