I think there may be a problem with the switch itself. There's a little nub or ball that is held on by a spring. If that ball or nub is missing, it will no longer click into place. Either that, or the receiver is worn down so the ball or nub doesn't have a definite hole to help click the selector into place.
I've had some issues with different brand selector switches on different guns. You might need to dremmel a little bit to make it fit but otherwise it should work.
"Any punk can shoot from across the room but it takes a real man to get close enough to stab"
"Why cause a huge disturbance when you just wanna kill ONE guy?" - Chris Rock
Last edited by jtf2-phalanx; May 12th, 2010 at 18:58..
Reason: more info