Ah..interesting you should mention that. I have the same problem on longer rides, but just with the jersey itself. Once it got so bad they were bleeding! Scared me when I read Lance's book and he described that as one of the symptoms he noticed before he was diagnosed with cancer.

But since I still seem to be here and riding I don't worry too much.

Now I put band-aids on. Sort of like pasties. Hope nobody ever sees me with them on!