I'm not sure this is a GroovyMAME issue, but I found some strange behavior with Gauntlet II. There is a vertical line/screen tear on the left 25% or so of the screen. You can see it right when starting a new game, the 'mortar' between the bricks on the floor is wider along that line. As you walk to the right, you can see the screen tear along the same line. It seems more like an emulation error than refresh. The strange thing is that Gauntlet I has the exact same resolution and does not exhibit this behavior (at least not that I can see). Does anyone else see the same?