I realize now that this may have been a more appropriate place to post my issue with 89.0 and Mavericks but I placed a thread in Help before that realization. As I said there, my mouse does not act properly, almost as if the box that the mouse acts within doesn't move with the window. As a result, the game works fine when the window isn't moved from where it opens but if you move the window, the brush moves offset from the mouse.