It looks like the collector is still running for some reason; of course, while it is running and has that proc filesystem open - it cannot be unmounted. So I would look into why the collector is not quitting when it should - we should kill it (or ptrace kill it I forget which - and then it should die) ;-)
-- michael.me...@novell.com <><, Pseudo Engineer, itinerant idiot -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org