Plain Text printing issues

I'm attempting to print to a networked konica printer. No linux drivers that I know of exist, but we've always used HP 5si drivers and have had good results.

We just loaded a box up with CentOS 5, and now when we print any sort of file from the command line (lp -dkonica <filename>), the text is enlarged and looks some what ugly. However, when I print off a test page from system-config-printer, the page looks fine.

I've tried removing the queue and recreating it, as well as tried some other drivers.

Any thoughts?