I jailbroke and unlocked my iPhone 2G but after a day or so it'll randomly reboot into recovery mode. It doesn't seem to matter what I'm doing or what jailbreak method I'm using. I've tried both custom firmwares and using the stock one with redsn0w (3.1.2). Today, for example, it rebooted into recovery after I launched the iPod app. It freezes, restarts and presents me with recovery.

Any ideas?