im not sure whats wrong with the first part about the - button. although the part with the long movement is most likely because the sensor bar cant find were the remote is. say if you swing it to far behind you for instance it, the sensor will prolly loose track of were it is. if not try calling maybe nintendo can figure it out.
personally i dont own a Wii yet but i know some stuff on it so what i said is just an assumption on what might be wrong
Also try putting your sensor bar at a place with a better angle. that might fix the distance part.