My B2620 doesn't seem to understand the quarter inching either. I haven't given up on finding the right combination, but it sure is touchy. I don't care for it too much yet when box blading, etc. If you hold the lever in, and are very careful, you can somewhat control where the hitch stops, but otherwise it just jumps six inches........ I'm probably doing something wrong, but I thought I understood it pretty well. If I ever have a different tractor, it will have true position control.