I solved this problem by installing a USB 2.0 card in my pc. Apparently it's not possible to connect via USB 1.1-A port across a 2.0 cable to a 2.0-B port. And exchanged the Lexmark for an HP. Once I got the card seated properly, I was off and running without a hitch, and can now print from the PC as before.
It took a Comp USA sales clerk to point the problem to me. Kudos.
2.0 cables usually say "backward compliant" on the package. That means where both ports are 1.1, and the cable is 1.1, a 2.0 cable will work. It does NOT mean you can hook up a 1.1 to a 2.0 using the 2.0 cable.