after a 'mount --move', there is 2 entries in mount output

[solsTiCe d'Hiver]

hi. 
here it is:
# mkdir r1 r2
# mount -t tmpfs none r2
# mount --move r2 r1
# mount 
[...]
none on /root/r2 type tmpfs (rw)
/root/r2 on /root/r1 type none (rw)

it seems to me that there is a duplicate entry ? the first one ? and why is 
the type 'none' for the second entry ? 

then
# umount r1
# mount
[...]
none on /root/r2 type tmpfs (rw)

# umount r2
umount: none: not found
umount: /root/r2: not mounted
umount: none: not found
umount: /root/r2: not mounted

i run a 2.6.19.1 kernel on an archlinux current with coreutils 6.6