Problem(s) Encountered:

The most severe problem was the guider and guide probe failing or malfunctioning.

Apart from generally not providing accurate positions for possible guide stars via Jskycalc (which may have to do with the pointing problem), the guide probe showed some erratic behavior.

At one point during a routine procedure to put the object into the slit, the guide probe would not move when given the dy  command in the MIS window. dx moves, and moves of the telescope apparently worked fine (as I could see a guide star moving appropriately when dx commands were issued, or the hand paddle was used in any direction, including y).

In addition, the guide probe did not move to y positions issued either by Jskycalc or in the xMis window--that window would INDICATE that a move in y had been made, but looking at the screen, one could clearly see that

nothing had happened (star stayed in exactly the same position).

Furthermore, the guiding itself went fairly poorly, as positional errors would not be dampened, but rather increased rapidly -- despite having the recommended settings for X and Y speed.

In order to get objects into the slit, I manually jogged them in their after having calculated have far to move. A bit cumbersome, yet not critically destructive.  The biggest problem, however, is that the guiding fails ! For longer exposures, that it obviously a huge problem - I basically reverted to the old fashioned  put a box around a guide star, and keep it manually in there  procedure, but given the rapidity of it marching out of the box, this is very cumbersome.

Solutions:

The control port on the guider was erroneously set (should be LPT378, as stated in the Autoguider Manual, section 2.1.2).  Looks like a default reset was accidentally issued at some point last night.  I’ve gone ahead and reset that back to the correct setting.

The last problem checked was the guide probe.  This turned out to be the most problematic.  It quickly became apparent that motion in the y-stage was not occurring.  Attempting to reset the MIS (drive the guide stage to the limits, 0,0) would not complete.  Fortunately with OSMOS installed, I could look into the port to check for stage motion.  There was none, although I could hear the motor turning.  Further checking and it was confirmed that the drive belt had split.  At 1430, we removed OSMOS and the bottom plate of the MIS.  The linear drive screw had to be removed to pull the belt, as did the motor and encoder wheel.  This is nontrivial, but we were still able to get things swapped in time for Paul and Tony to catch the bus down.  I stayed behind to get OSMOS cabled up and bring the software back online, as well as to consult with the observer (plus a few loose ends at the 1.3m).  

Just heard from the observer and all is running well on the 2.4m tonight.