Oh yes. Had this happen with the band I'm doing now. The bass player apparently has students too, which I find somewhat disturbing. At least he admitted that he hasn't practiced enough - which there was plenty time for though, we'd already had to book an another separate weekend for just tracking bass, since we couldn't get it done when we previously tried, and even with the extra three days we almost ran out of time. Luckily he was fine with having the guitarist play the most difficult parts, all of which the guitarist nailed in almost single takes. I'm going to love editing it... but I guess it's only fair, since the drummer and guitarist were so tight that tracking and editing them was a breeze. I'm consistently finding a link between pot and lack of motivation to practice; in this case it was clear that the bass player preferred smoking pot rather than actually honing his instrumental skills... But who am I to judge? I just find it sad when a person is serious about becoming a professional musician, yet lacks the motivation to make a serious effort to be one.