Has anyone ever encountered difficulty mounting Dymo LabelWriter printer drivers?

I have a Dymo LabelWriter 310. I have been able to get it to work on Classic, but the procedures are so awkward as to make usage prohibitive. I have never been able to get the printer driver to mount under OS X. Dymo technicians have suggested a dozen or more possible solutions (They've been trying hard), but none have been successful. The stumbling point comes when I try to add the Dymo printer using Printer Setup Utility. The browser detects the printer but the ADD option remains greyed out in the drop down menu. This of course means you can't add the driver.

Some other details: Connects with USB (no hub); only one other printer currently active (GCC Elite 12/1200); have tried many variations of restart/trashed preferences; tried deleting all other active printers, repairing permissions, re-installations, soothing words, curses. Other programs have worked fine, eg Canon scanner, Intuos graphic pad, various word processors, Adobe CS2, etc

Setup: iMac G4/800; MacOS 10.4.6; Dymo LabelWriter 310, v. 7.5 (have also tried v. 6.1 and older versions)

Any suggestions?

Vlad James