LinuxQuestions.org - Cannot print to wireless printer

I have a Brother HL-2880DW on a wireless local network, Ubuntu and Windows 7 laptops and a Slackware 10.2 desktop. The first two print to the wireless printer flawlessly, and the Slackware desktop will print a test page when commanded from the CUPS setup webpage. Here's the printers.conf file:

# Printer configuration file for CUPS v1.1.20
# Written by cupsd on Thu Aug 9 15:26:52 2013
<DefaultPrinter brother>
Info Brother HW-2880DW
Location downstairs
DeviceURI lpd://192.168.0.101
State Idle
Accepting Yes
JobSheets none none
QuotaPeriod 0
PageLimit 0
KLimit 0
</Printer>

CUPS is working and prints perfectly over the wireless router to the printer from the CUPS configuration web page. Jobs show in the spooler. I can telnet, ftp and browse the Web through the wireless router to the Internet, but when I try to print a document (as gsmith) from the command line, this is the error message I get:

gsmith@harpo:~$ pr cups | lpr

Status Information, attempt 1 of 3:
sending job 'gsmith@harpo+974' to brother@localhost
connecting to 'localhost', attempt 1
cannot open connection to localhost - No such file or directory
Make sure the remote host supports the LPD protocol
and accepts connections from this host and from non-privileged (>1023) ports
Waiting 10 seconds before retry…

Clearly it's a network problem on the Slackware computer, but I can' seem to see it. Any thoughts?