I only received two responses to this question. Maybe these printers are new enough that not a lot of people have them, or maybe most people don't have issues when they set them up (which I suspect is the case)
The responses, none of which helped (but thanks for the time to reply) were:
We had this issue with our Xerox wide-format printer turned out we didn't have enough memory on it, once we cut the dpi down to 200dpi from 400 it started printing full sheets. ======= I had a bunch of trouble getting a new install of WF3 to print properly while using .pcf files that had worked perfectly in 2001. It seems that in WF3 my .pcf settings were only being correcly applied if, after selecting the desired printer from the "Destination" drop-down, I clicked on the "Configure" tab in the print dialog box. I don't need to change any of the "Configure" settings... I simply need to open and close this dialog.
To clarify, I need to step through these mouse clicks: Print > select desired .pcf from "Destination" dropdown > Configure > OK > OK > windows print manager opens. =======
I did already have my mapkey set up per the second suggestion, so that wasn't my problem.
After a lot of playing around with it, and testing different settings, and testing different printers with known good data, I finally discovered that there is a problem with our printer driver. We route all printer requests thru a Linux server, and something in that driver on the server is mangleing the prints to this printer.