Many of the Contax cameras I see have severe shutter damage due to a finger being used to push the shutter curtains in an attempt to "loosen" them. Pushing, pulling or interfering with shutter curtain travel can cause severe shutter damage. When the shutter curtain is pushed or prodded in an attempt to correct a problem it is almost certain that damage will result. The little slats are connected to each other by little tubes of aluminum in the Contax IIa and IIIa, and by little brass rods in the I, II and III. When these tubes or rods are bent the unrolling of the slats from the shutter roller is impeded. The result of a bend can be a troublesome noise when the camera is wound or the bend can impeded shutter curtain travel to an extent it will slow down the high speeds. This damage can never be completely corrected and in severe cases the only remedy is to replace the damged slats.
There is no shutter malfunction that can be corrected by touching the shutter curtains. So no matter what ever ever touch the shutter curtains for any reason.