If SME is the ONLY file server on your network, You can switch this to YES.
If you have Windows PDC or your OpenBSD/Samba is acting as PDC and workstations configured as DOMAIN (not Workgroup) members, you will need much more to do that just change NO/YES switch.
Post more details on how your servers are configured if you need more detailed advice, relevant sections of smb.conf from both servers might help to find out the current configuration of your environment.