All of the mast fittings on the Stealth carbon mast are rivetted. I don't know of anyone with major problems as a result. On the other hand, being new to the class at the time, I took the precaution of through bolting the upper and lower diamond tangs <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> (it does no harm!)

If I were going to rivet into carbon, I'd drill the hole, paint it with epoxy to seal the ends of the cut fibres, and then pull up the rivet. Ideally I'd want to get a backing plate on as well.