I have an old Nikon FE that I still use for shooting Infrared film. The last film I put through it shows that the film advance mechanism is slipping. i.e. some frames have multiple exposures, not necessarily aligned with the first. When I rotate the film advance lever, the take up spool slips if there is too much friction from the film in the cassette. It doesn't take much to stop it moving. Does the film advance have some kind of slipping clutch mechanism built in to it? Any suggestions how to fix it?