Problem(s) Encountered:

No problems, except xmis refused to execute dx and dy commands for some reason, though it did execute changes in absolute position.

Solutions:

The apparent malfunction of the MIS guide probe dx and dy commands reported a few nights ago turned out to be due to the fact that requests for moves >= 1000 units are ignored, with no error message.  There is no good reason for this.  When I tried 999 units, it worked!