Magic Mouse no longer works on desk surface (varnished wood)

My magic mouse used to work fine without a mouse pad, but recently has become almost non-functional. As I move the mouse around on a varnished wood surface, it now seems to lag badly, almost stopping completely despite contined movement of the mouse. I've tried trashing the prefs, uninstalling MagicPrefs, reinstalling MagicPrefs, dumping MagicPrefs for BTT, etc. Nothing seems to work. I do have to regularly clean the plastic tracks on the bottom due to a buildup of dust, etc, but that, too, does not improve my performance. Does anyone have other suggestions for how to fix this problem? It would be a shame to have to use a different mouse.