If the settings in MAME got changed, you have 2 choices. Delete the default.cfg file and restart MAME When in MAME, press TAB on the keyboard to bring up the options menu. Enter the controls menu and choose what controls you want for your layout. If you are using the defualt MAME layout, I'd recommend option 1. If you have modified things significantly, you probably will want to just fix what has gotten screwed up by going with option 2.