Mac Help: PS2 Guitar w/ USB Overdrive Problem

[TheCheatOSX]

We've been rocking out 2 player style on a Rock Band wired guitar and a keyboard with no problems but my coworkers and I agree we need two guitars so we can ditch the keyboard! I've got a PS2 guitar so I purchased one of those cheap PS2 to PS3 converters off eBay to connect the PS2 via USB. I've also got USB Overdrive as I understand this is required to map the keys for use in FOF. Here's the prob: when I go to USB Overdrive and select Joystick, the interface is wigging out. It's like some keys are being pressed on the guitar in rapid succession and I can't make it stop to map the keys. The OS does seem to recognize the guitar and lists it as Twin USB Joystick in System Profiler as does USB Overdrive. Anyone else have this trouble? Could it be my adapter? Running OS 10.4.11. Thanks for any help you can give.

[ADH]

sounds like a wammy bar thing (try holding it down and moving it around to see if it will stop)
did you try to callibrate it in the joystick settings.

[TheCheatOSX]

Well, I tried holding the wammy and I also tired another guitar and neither worked. I don't see a calibrate setting in USB Overdrive.

Is there a difference between a "PS2 to PS3" adapter and a "PS2 to USB" adapter. I just figured they were one in the same and bought a PS2 to PS3 adapter.