Purchased Kel-Tec P-3AT, love it ! Decided to add the Kel-Tec trigger shoe, makes a lot of difference to me in the trigger pull. Simple installation followed directions to the letter. However, after about 50 rounds shoe comes off. I have tightened the set screws to the point of something bad happening and even added a dash of lock-tite, thinking maybe the screws were backing out. has anyone else had this problem or can anyone offer suggestions or solutions ?