Mission: Impossible [To Understand Kernel Messages]

VFS: Busy inodes after unmount. Self-destruct in 5 seconds.  Have a nice day...

This on a 2.6.11.8 SMP box running FC1 with about.... 40 nfs mounts? Average load time is around 1.0-1.5, and theres lots of java daemons running in the background... The above message popped into dmesg about 6 times, once every.... so often (no timestamps).

Yeah... I googled around but couldn't get a good idea of what the hell this message is talking about. Ideas anybody?