Hmmm….
mount -t smbfs, or, even better, mount -t cifs (both are to connect to Samba, the later is a newer and improved standard though), should be preferred over smbmount imho.
That said, I remember there was something about uid & gid (user id and group id) parameters when mounting Samba drives imho, to let it know which user & group should “own” the remote files… have you set those correctly?