My GP2X won't use any batteries except the ones it came with. When I try to use them, sometimes it will work for a while and then the screen will glitch and freeze, or sometimes it will glitch and freeze at the loading screen. It works fine with the batteries it came with. The only difference between the two kinds of batteries I can find is that the ones it came with are 1.5V batteries and the ones that it cannot use are 1.2V batteries. The batteries I have tried are Rayovac rechargable NIMH 1.2V batteries, and Energizer 1.2V NiMH batteries. The GP2X also works with a 3V power adapter from radio shack. Could it be defective?