I recall having a similar issue a year or so ago. I wanted to be the super melow bass player, just doing my thing. I was having similar problems, but with a harmonica player. In the end, I decided it was better to be an a**hole than have the music suffer. I recall my buddy in the band asking me what the harmonica guy did to piss me off. I explained it as I would rather hear from band members at rehearsal that I was screwing up, than hear it from an audience member at a gig. Since then its kinda been our rehearsal policy, brutal honesty. It works really well for us.
