has this happened to anyone else

[BrianG]

Actually, the set screw simply adjusts the shift point, but since he has it locked, that could be removed and it won't affect anything (actually it could help since it can't come loose and float around inside there).

My first thought was the pin as well. Is it the pin actually on the clutch, or is it the pin that holds the gear to the shaft? If it's the latter, there is a sticky on how to fix that so it's tougher. If the former, then it might have been a weak pin and simply replacing it should be fine.