I have not encountered this problem so I don't have a guess what might be binding up but the McClickie module can be taken apart so you may be able to rectify the situation. With a thin flat blade screw driver, you should be able to seperate the two outer plastic pieces. Work one side and then the other so that the two parts separate from each other while staying aligned on the Z axis. Put the blade into the area on each side where the outer contact ring drops down towards the rear of the switch. There are 4 latching arms that hold the two parts together and you want these arms to come out of their sockets evenly and straight, if that makes any sense.
There may be excessive grease inside causing the problem?!? If you fail to get it fixed, send me an e-mail and I can send you a replacement switch in the mail, no problem.