are you currently going through USB/PS2 (with keyboard)/or Gaming adapter? If you are going throught PS/2 then you need a ps2 keyboard plugged into it or it wont work. If you are going through a game adapter (such as the PSX), there are button combos that change the joysticks from digital to analog and that will cause them to stop working. I use the PSX adapter and pressing the white button on the side plus other buttons at the same time it throws my xarcade into analog mode and mame wont respond when I move the joysticks. Pressing the white button on the side (which I use as "insert coin") plus the top left black button on that player (the button you would use for high punch on mortal kombat, or weak punch on street fighter) it puts the joystick back to digital mode and it works fine. If you plan on using the xarcade for MAME the absolute best configuration is the Xarcade PSX adapter, then plugged into 2 different PSX to USB adapters. This makes the computer think the xarcade is a gaming controller rather than a keyboard. The purpose of this is, USB keyboards are limited to how many buttons can be pressed at the same time. So if you're playing a game like NBA hangtime with 2 players, if player 1 is holding a diagnal andturbo and shoot, and player 2 is doing something similar, one of the players buttons wont be registering. The PS/2 with a PS/2 keyboard is supposed to depend on the keyboard to determine how many buttons can be pressed at once. Ive tried maaaaaany PS/2 Keyboards and none of them worked when pressing down every xarcade button at the same time. The only thing that allows ALL buttons to be used at once is the PSX to 2 different USB adapters (one USB adapter for each player). Hope this helps. Hope I wasnt too confusing. If you need anything clarified please ask.