It's happened more than once, with different cds, but not necessarily everytime I try to rip cds. So it's one of those annoying intermittent problems. Typically, when I'm ripping cds, I'll grab a stack of five or six, and work my way through them. When the problem occurs, after ripping a few, MC will suddenly start behaving in the fashion I described.
1. Insert disc
2. MC attempts to lookup track info in YADB
3. A series of 'connecting to YADB' dialogs are displayed, one per track. (Don't recall exact wording of dialog, that's roughly what I remember. If I can reproduce again, I'll post the exact dialog wording)
4. After displaying a dialog for each track, no track information is available for the cd.
5. Any attempt to play the cd, or rip the cd, result in a repeat of the 'connecting' dialogs.
6. Restarting MC corrects the problem. Track info is available in YADB.
I'll try ripping another set this afternoon, and see if I can reproduce it again.