My girlfriend's work computer now has Linux on one of the partitions, and for the most part it's running fine--except that I can't seem to get the network printers configured right. There are two of them: a Lanier MP 7500/LD275 and a Lanier MP C3000/LD430c, and Linux seems to have found them both automatically. I'll go through the steps of what I did, and what exactly went wrong.

I went to Administration > Printing, and clicked the new printer button. It searched for printers and found them both, listed under "Network Printers." I added them as new printers in succession. However, when I clicked "Print a Test Page," it failed saying there was a broken pipe. The device URIs were saved as socket://[ip address]:9100. I changed these to lpd://[ip address] per some online tutorial, which at first looked like it might have worked (but didn't). Then when I tried to print a test page, it first said Processing (and sometimes even Processing - printing test page, 4%, but always subsequently displays Idle - /usr/lib/cups/backend/lpd failed.

Help! What do I do? It seems like Linux can find these printers just fine, and the drivers seem to be in place, so what's going wrong?