CIFS VFS: server not responding during shutdown

[Matteo Riva <muradin@gmail.com>]

When I do a shutdown while I have windows shares (manually) mounted, I
get a timeout before the shutdown completes.  The message I get on the
console screen is:

	CIFS VFS: server not responding
	CIFS VFS: No response from cmd 50 mid 15

the shutdown process hangs for half a minute or so before completing.

The windows host machine is responding: I can unmount shares manually
with no problems, but if I leave them mounted I get this timeout.

Also, I can't find mention of this under /var/log (I had to write it
down from the console screen).

What can cause this behavior?

Thanks