I had the same issue. I have beaten Kinect Sports, Kinect Adventures, Hulk Hogan, Kung Fu Panda 2, Kinectimals, all the Kinect Fun Labs games, Fruit Ninja and then this game wont work.
I didnt get an error but it just wouldnt register my feet. This game just requires a lot more space. I brought it to the living room and it works like a charm. So you might need to do some rearranging to make your play space bigger.
PRE-PATCH MARATHON Trials HD- (10/3/09-11:38 PM)