Just another idea to check George. If you repeatedly slew to the same object (say a star) does the scope point to the same spot each time or go to a different spot. You could then repeat this test on a couple of different stars and see if the scope always shows the same amount of error (example: always points, say, 10 degrees in right ascension away from the correct target). This would suggest something wrong with the way the scope is set up. If it goes to a different spot, each time you slew to the same object from the same starting point, this would suggest that there is something seriously wrong with the mount.
This may not help you solve the problem but may help you find out if you have a faulty mount.
  