OK, so I bought a 1000mA universal adapter (thats 1000mA at 12v.. its rated for 1400 at 3v)... Its set at 3v, definitely center negative.. I plug it in, the gp2x switches on and I hear the startup sound, but I get the fuzzed up screen, as if I had dead(for the gp2x) batteries.
It works fine...