Samba printing problems after upgrade

Sometime after I'd upgraded the hydrus printer/file server to FreeBSD 8.1, I discovered that printing from windows clients was not working. As far as the clients were concerned, a print was successful, but nothing appeared at the printer. During the upgrade to FreeBSD 8.1, I'd elected to move to Samba 3.4 from Samba 3.0, so I figured that was the likeliest cause of the problem.

I checked all the samba log files, but there was no trace of any errors. I looked at the smb.conf file for mismatches between it and the real world. The printer stanza was defined as follows:

   comment = All Printers                                                       
   path = /var/spool/samba                                                   
   browseable = no                                                              
# Set public = yes to allow user 'guest account' to print                       
   guest ok = no                                                                
   writable = no                                                                
   printable = yes 

Hmm, looks OK. How does that compare with /var/spool?

  clientmqueue/   lpd/       opielocks/     samba34/
  lock/           mqueue/    output/

Aha! A mismatch between the spool directory defined in smb.conf and the one that actually existed. Reviewing the provided samba 3.4 smb.conf.sample confirmed that the new version had renamed the spool file (or I had at some time in the past).

Modifying the name of the spool file in smb.conf and restarting samba had printing working again.