I just bought a 32 gb iPod 3G touch off of amazon.com. It has the latest firmware. It was fine for about a week. Then, I was using the app Eliminate Pro, a 3d first person shooter, when the screen turned green, and then the ipod turned off and started to reboot (apple logo on screen). Since then this has happened when using the following apps:

Eliminate Pro (after ~15 Minutes of use)
Tower Madness Zero-3d tower defense game (after ~15 minutes)
NOVA-3d fps-(crashes every time I start the second level)
Battle Bears 1.5-(crashes every time I try to start to play the actual game)

I don't know if this is related to the apps or the iPod itself. The only similarity I can see between the apps is that they all run 3d graphics. But other games I have do this too and are fine (COD: Zombies; waterslide). I've tried reinstalling the apps both downloading them directly onto the iPod and syncing them from itunes. I have also restored my iPod using itunes. This seemed to fix the problem, but since then it has crashed a few times. I have used the app System Activity Monitor to clear unused memory, but this didn't work either. I dropped my ipod once, but it was a very short fall, and I have a case on it.

I guess I'm trying to find out if anyone else has this problem, and if it is my ipod acting up or the apps. I still have my 90 day warranty, so I could send it to apple.

Any help would be appreciated. Thanks in advance.