Hi Julie probably the bearing seal is clogged on the paddle shaft. You probably need a new bearing or try cleaning the bearing until the paddle rotates freely. Failing that dismantle from the bottom of the mixing container taking circlip off and checking all parts for wear ,could be the part that engages the drive has lost a lug, if not replace the bearing. if it is the lug that has failed you need to have one made up since they do not stock spares anymore
Christine
March 2009