I have a cue with a 11.50mm shaft size. This is the 5th time in the past year that my ferrule has came loose. I have had two different cue repairmen put on new ferrules, but it keeps coming loose. Does anyone know why this keeps happening to my cue? I'm going to get rid of it, because it's driving me nuts. Plus the shaft is slightly warped, and so is the butt. Does anyone know what causes a ferrule to come loose so often??