Just wanted to add one more thing I tried ... to add a "regular" printer driver ....
From the Windows 7 Control Panel, Devices and Printers page, I did "Add a printer" > Add a local printer > Use an existing port (LPT1:) > Epson PX-V500(M) (randomly chosen from list of printers). I set this new printer as the default printer. I then rebooted. However, I still get the same error (as my post above).