Symptom
A newly added printer via UMC is not displayed in Samba.
Solution
The printer should be found in the listener.log. If not make sure the replication is working and the directory-listener is running.
Investigation
You can check, if the printer is added to cups:
lpstat -p |grep <printername>
And with this command, it should be found in samba
rpcclient -UAdministrator localhost -c 'enumprinters' |grep <printername>