Problem(s) Encountered:

The filter wheel got stuck when moving between filters at the beginning and at the end of the night.  In neither case was the pointing angle extreme. One was at sec z = 1.25, and the other was at zenith.  Reinitializing the MIS fixed it.  But, since these were the only two times that I changed filters, it seems like it could be a persistent problem.  It happened to me once a week ago, and also to another observer last weekend according to the reports.

Solutions:

A number of things were done to try to resolve this issue.  The FW was disassembled and put back together; the controller was reseated, and filters were installed symmetrically around the wheel now.  There have not been further issues for well over a week.  Not sure why, but I’ll consider it fixed, at least for now.