Mike
I had the same problem, same belt, but it only stays in the forward position. I started to have problems with it after I started to have problems with my battery. I am going to put a new battery in, and let the switch reset (manual states that it needs to be done sometimes) and see what happens. In the back position, you can at least use it and unbuckle it to get out. If you find out anything, let me know. I'm wondering the same thing. Every once in a while it tries to work, but will not. I have used the tool and moved it to the back position, and it will move forward again, but not back.