I just bought a used 2010 Edge M21 in nearly perfect condition. Took it on its maiden voyage and it was great! One problem arose on our third and last day of the trip: the large window covering behind the couch will no longer "roll down" completely. It will get about 1/2 to 2/3 of the way down, and the roller seems to get stuck. I haven't taken the thing apart yet, but has anyone else run into the same problem? Any information is greatly appreciated.