[Samba] Strange behaviour with shares

[sp4mmed Hotmail]

I have recently discovered a rather strange happening with regards to 
shares on one of our servers.
A user wanted to access a folder on our public directory and typed in 
the following in their explorer:
"\\server\share installs"
What happened then is the strange part: they came face-to-face with the 
root folder of the server!
I'm not an expert and the shares were set up by a techie who has since 
left the company, so I couldn't ask him what he had done.
Here is a snippet of the samba.conf file that pertains to the above share:

[server]
        path = /shares/share
        read only = No
        create mask = 0777
        force create mode = 0777
        directory mask = 0777
        force directory mode = 0777
        guest only = Yes
        guest ok = Yes

As I said, I am not an expert, but the create mask, directory mode, etc 
seem a little strange to me.
Our samba server version is 3.0.23a-1

If anyone has any suggestions or needs any further information with 
regards to this, please let me know.
I would hate to think that I have a broken server implementation here. 
(Although I wouldn't be too surprised!)

Many thanks