This bug has been opened here: https://bugzilla.ubuntu.com/8309

"I try to create a shared folder using shares-admin.

1. I open shares-admin.
2. I select the path, the protocol (SMB, of course), and in "Share properties" I
put no name (leaving the "name" field empty).
3. I click "ok", and click "ok" again in the "shared folder settings" window.

Now I have a /etc/samba/smb.conf file with a section named "[]":

[]
path = /home/ricardo
available = yes
browseable = yes
public = yes
writeable = yes

That "empty"-named section is wrong, and samba complaints about it. And that
wrong section doesn't appears in the shares-admin's "shared folder settings" no
more, so there's no easy way to delete it (the only way is to edit
/etc/samba/smb.conf by hand).

I think shares-admin would get the folder name as a "share name", when the user
doesn't gives one."