Hi Art sorry to read about your troubles, i had a 105 for about 4 years and had no problems with the drives, maybe i got a good one and you got a bad one. I tried using the rear port for imaging without great success the only way to use it without fouling the mount is in polar mode but in the end i gave up and upgraded to a scope that is designed for hanging stuff off the back without fouling the mount. The etx is a great scope and mount for the money, i think you are being a bit harsh and are using it for what it was not designed for, like you say it is a nice grab & goto scope.

Duncan