Samba - why isn't "force user" working as I expect?

[Chris G]

At the end of my smb.conf file I have:-

    [Scans]
            comment = Digikam scans for chrisx
            path = /home/chrisx/pictures/Scans
            writeable = yes
            force user = chrisx

    [xpIsbd]
            comment = ISBD on XP
            path = /home/isbd/xpIsbd
            writeable = yes
            force user = isbd

I thought this would mean that when I connect to these shares from my
XP machine (on which I am user chris) any files and/or directories I
create there would be created as users chrisx and isbd respectively.

However it's not working, I can connect to the shares without any
problem but files/directories are always created with owner chris.

What am I doing wrong?

(This is samba 3.0.28a on Fedora 8)

-- 
Chris Green