I had the same problem... turned out I was wearing shorts that were too big. It took a kind sales rep to show me the error of my ways.

No more catching my chamois on the nose of the seat. Go down a size. The shorts should fit like a skin... yeah, I know... that whole sausage thing bangs us grrls the wrong way BUT better to be a sausage than shish-kabobbed on your saddle nose.

spazz