looks like you need to tweak the resolution that your game runs at inside advmame. Are your other games stable ?(choose a game with a different resolution than the one shown here--like pcman or something). if not, maybe your sync connection needs to be adjusted--On your monitor cable you should have a horizonatal sync and a vertical sync, some monitors only accept horizontal to sync, other can have horiz and vert. combined into sync. need more info I guess...