There should be a shoulder in the frame and on the screw. The screw should bottom out before it hits the cylinder pin. It sounds like yours is just a tad long and is pushing up on the pin binding the cylinder. Take the pin and cylinder out. Put in the screw and run it into the frame. If it hits a positive stop then just shorten the tip a bit and retry it. It it goes all the way through the frame, then you will have to put a little loctite on it.