My Ric 4003 has had a problem for a while where the truss rod vibrates (buzzes) inside the neck. This is different from fret buzz, which is a far more common problem that I'm not experiencing with this bass. Anybody know what I should do? It's really annoying to have this vibration in the neck, though it doesn't affect the sound through the amp much. Do I have a bent truss rod that needs replacement? Anybody know someone in Portland, OR who can help me? Thanks.