After trying and failing with some debugging steps that have worked for me in the past, I tried running the print utility that was installed with my driver (I am using a Hewlett Packard 832 C DeskJet). I told the utility to print a test page and I got an error that said that Classic had control of the printer. I stopped Classic and everything worked fine again.
[Editor's note: This also happens with my Epson when Classic is running - I either have to pull the USB cable and reconnect it, or stop and start the print job in order to get the printer to print. If Classic is not running, all is fine.]

