samba - Apr 2004 - Cannot umount as user

I have to connect to XP-windows machine where my colleague have choosen 
to make a share name with a space in it.

I can mount to just fine having in the fstab the following line

//machine/direc\040tory /mp smbfs password=,user,noauto,rw,exec 0 0


However when I try to umount, I get

umount: /mp mount disagrees with the fstab


In mtab I find

//machine/direc_tory /mp smbfs 0 0


How do I solve it so that 'space' is not replaced by
'underscore'

I running RH9

Torben