Hey, I ordered a 275mhz GP2x from gbax.com last wednesday and it didn't come untill today and at 270mhz. I recieved no batteries and the usb cable I got with it didn't work. I tested it with some 800mAh batteries and it worked great, I found an old usb cable and was going to test it with an mp3 so I sent an mp3 to the NAND memory but before it finnished the battery warning light came on and it turned off. Now I assume the batteries are not sufficient to run the unit since I've read about 1000mAh+ batteries being used, I do plan to get an SD card and putting an MP3 on the NAND memory was just a test. What batteries should I be using? Thanks.