I have had my arcade setup for about a year but had not played it in a few months and I never had this problem before (I guess I hit something or a guest did last time it was used). I just noticed that when I am in ANY MAME game, if you pull down on the player 1 control stick, the Master Volume control pops up at the bottom of the screen. It only does this inside each game and not anywhere else. I have hit tab and gone through every input setting I can find and nothing shows player 1 "down" should open up master volume controller. I would have thought it was in the "General" settings since it happens in all games but I am at a loss as I think I have checked everywhere. I have all windows hotkeys, shortcuts, etc disabled and it only does it when in an actual game.
I am running Maximus Arcade with an Xtension 2-player control board with track-wheel and "down" works fine when within the Maximus game selection menus. Only place it activates is inside the actual games. Once active, if you joystick right or left, it changes the volume. Only way to get it to go away is when you pull down the controller again. It really makes playing a game difficult.
Any ideas? I have attached a picture of the screen once the control bar pops up.