It isn't that the smart card reader is needed to print, it is that the smart card reader was enabled as the authentication method, and print was set to require authentication.
So what is it set to authenticate to?
What happens when you swipe your card at the printer?
I have installed a Versalink C 405 and I can't print anything. The message is " A smart card reader is required to print. Please verify that the Smart Card Reader is connected and the driver is instaled properly". I connected the Smart Card Reader and the driver is installed from the CD that came with the printer.