[Samba] security = user

[Henning, Brian]

Hello,
I am having a slight problem with my samba configuration. When i set the
security = share i can see shares just fine as a guest, but when i change
the security to security = user then i can't even see my shares. I get the
following error: The network path was not found.


snip of smb.conf

...
[homes]
        valid users = %S
...

do you know what my problem could be? 

thanks for your help,

brian