bt0: mbi at 0xf86aa9b4 should be found, stat=81..resync
   bt0: mbi at 0xf86aa954 should be found, stat=81..resync

   Can somebody tell me what these mean?  dmesg output below...and the card 
   is a bt946...

It means you got an incoming mailbox interrupt, but no incoming
mailboxes were full.  This *could* indicate a cache coherency problem,
but if your machine works otherwise, it's more likely that it's just
because of a (perfectly legitimate and unimportant) race condition.
The message should probably not be printed by default.