An hour and a half later, we have isolated it to what appears to be a malformed COM error response from TheSky when it is called to Sync(). This is an unusual problem because most people run TPOINT, and the driver is set to "inhibit sync to protect TPOINT model", and thus ACP never calls TheSky to Sync(), instead ACP jogs it to center the object. In this case, the COM error is not being trapped by ACP's Windows Script error handling... instead somehow it is causing the script to silently stop. That's why I suspect the error response is somehow strangely formed. Anyway we were able to trap it in a simple Javascript and it is "Object not set to a reference to an object".

John's going to continue to pursue this further as I have another online session and it's out of my hands for sure anyway.