samba - Mar 2015 - Failed to get GUID / failed to construct printer info level 7 - WERR_BADFILE

We have about 72 printers served from cups to Windows clients using samba. 
Point and print works for all of them except 4.   When trying to connect to
these printers, the Windows computer just says "Windows cannot connect to
the printer.  Operation failed with error 0x00000002."

And in the samba logs for that system, I see the following for each queue that
has problems.
------
[2015/03/12 15:52:55.729435,  0]
printing/nt_printing_ads.c:116(nt_printer_guid_get)
 Failed to get GUID for printer w229_xrx_7800_simplex
[2015/03/12 15:52:55.729642,  0]
rpc_server/spoolss/srv_spoolss_nt.c:4835(_spoolss_GetPrinter)
 _spoolss_GetPrinter: failed to construct printer info level 7 - WERR_BADFILE
------

A cupsaddsmb for that printer did not help, and neither did deleting the printer
from cups and creating a new one.  A brand new printer in cups with a different
name does work, however.  We're currently running the default cups and samba
( 3.6.23 ) on EL6, and our smb.conf is below.

For what it's worth, this seems identical to
https://lists.samba.org/archive/samba/2014-April/180409.html

Any suggestions would be greatly appreciated.

Many thanks,
Devin

------

workgroup = ADDOMAIN
server string = %h
netbios name = %h
log file = /var/log/samba/%m.log
max log size = 50
security = ads
dedicated keytab file = /etc/krb5.keytab
kerberos method = system keytab
realm = ADDOMAIN.COM 
passdb backend = tdbsam
username map = /etc/samba/users.map
load printers = yes
printcap name = cups 
printing = cups
guest ok = no
[printers]
   comment = All Printers
   path = /var/spool/samba
   browseable = no
   guest ok = yes
   writable = no
   printable = yes
[print$]
   comment = Printer Drivers
   path = /mnt/cupsdrivers
   browseable = yes
   guest ok = yes 
   read only = yes
   write list = root