Knoppix printing problem

I like Knoppix and would use it except for one problem. I cannot print with it. My hardware is an HP Pavilion zv5000 laptop with Athlon 64 chip, 512mb main memory, 60gb HDD, CD/DVD drive, etc., and Epson Stylus Photo R200 printer connected via USB. My problem is this: I seem to be able to set up the printer without problems, and the test page prints perfectly, but when trying to print something else, a letter in OO, for example, all I get at the printer is raw Postscript code. Apparently the code from the application is going directly to the printer rather than through the program that translates it to the codes the printer needs. Can someone with more knowledge of the internals of Linux tell me what's going on here?
BobI