I've just installed Stepmania (very happy with it so far) however I have a problem with configuring the arrows properly. Stepmania recognizes my mat (which is a generic GameStop DDR mat that I purchased a few years ago) and I am having difficulty configuring the center arrow. I set my up, down, left, right, up-left, up-right, down-left, and down-right respectively but I don't know where to set the the center arrow at since the only other inputs available besides those aforementioned are the "Start" and "Back" keys (which I've also configured for something else) The very center of my mat doesn't have an input so I'm confused about what steps to take (ironically enough) to fix this issue. Thanks.