[Samba] Samba 4, CUPS, and one slow printer

[Alan Schmitz]

I'm running CentOS 6.5, cups-1.4.2-50, and sernet-samba-4.1.4-7.  I have five Ricoh copiers configured as printers using RAW queues in CUPS.  Samba is configured as an Active Directory domain controller.

I followed the "Samba as a print server" guide in the wiki.  The [global] section contains load printers = yes.  The [printers] section contains the following:
  path = /var/lib/samba/printing
  printable = yes
  printing = CUPS
  use client driver = yes

All of the Ricoh printers are associated with the same "PCL6 Driver for Universal Print" driver through point-and-print installation.  The printers are configured on roughly 40 Windows 7 computers using a group policy.

Four of the five printers work great.  They're fast and reliable.  When my users print to the fifth printer, the jobs stay in the CUPS queue for between 5 and 10 minutes "processing".  During this time the data light on the copier stays on as if it's accepting a print job.  Even after the job says it's "completed" in CUPS, the data light stays on and the copier says it's printing the job for another 20 minutes.  Each job takes roughly 30 minutes to print.

While the job is "processing" in CUPS, I don't see anything running on the server that looks like it's trying to process or convert the print job.  There's nothing extra in the CUPS logs for the jobs that go through slow print queue.  I've also checked the settings on the printer under "View remote printers" in Windows 7.  The settings on the slow printer look the same as the other Ricoh copiers.

If I configure a Windows 7 machine to print directly to the copier on TCP port 9100 using the same driver, it prints quickly and reliably.

Any ideas why one print queue would be so much slower than the others?  How would I go about completely removing the printer from CUPS and Samba/Active Directory, so I could set it up from scratch again?

Thanks,
Alan