guest creation leaves 'certain' references to the filesystem
where it is created (supposedly /proc, /dev/pts, and /tmp)
which prohibits further unmounts of the affected filesystems


vserver vsap4 build -m debootstrap \
	--rootdir /var/lib/vservers/vsap --hostname vsap3.tpip.net \
	--netdev eth2 --interface 192.168.2.207/24 --context 43 \
	-- -d etch -m http://ftp.de.debian.org/debian-amd64/debian/


observed with:

  2.6.16-rc1-vs2.1.0.9, 2.6.15.3-vs2.0.1.2

fine with:

  Debian-2.6.12, 2.6.13.2-vs2.1.0-rc2, 2.6.15.3


confirmed with:

 2.6.14.6 (there with vs2.01, working without)