Generally jogging works just find for me and about the only thing I use the pendent for. It does feel like there is a sync between the detents in the jog wheel and the actual jogging from Mach3. Well, most of the time, one "click" on the wheel will cause a Jog of the selected distance but occasionally I will rotate the wheel one "click" but no movement of the table will happen. As this is a very benign failure mode, I just ignore it. I have never seen Mach3 freeze up. check to be sure you don't have anything else running on the system, even virus software etc. Does Mach3 freeze under any other circumstances besides Jogging? What about if you jog via the keyboard and not the Pendent?