I have the christmas village trolley set.  This is the one with the trolley that will auto reverse.  Out of the box it ran great.  Then the second Christmas it was up it seemed to run very slowly.  Now it won't run at all.  I've cleaned the track and tested the trolley on a standard track that is powered by a tranformer and the trolley runs great.  It's only on the special reversing track that it won't run.  Any sugestions?