Could be any number of things, not least of which are my suggestions :), I'm getting ready to head out to work so perhaps some kind soul can come to your aid (hint, hint). hopefully correcting and enlightening myself as a selfish bonus.

I'll be back some time this evening. I'm currently working on some toon style textures, so I'll post a successful glossy lip shader using a mask some time in the wee hours if no one has addressed your problem (or you solve the problem on your own).

Edit- Woops! Sorry Laurie, crosspost. I defer.