Printing documents with Lexmark X83.

I have a Dell Demension 4400, Pentium 4, Win XP, 40GB HD, 256mb Sdram, ethernet card hooked up to a cable modem for Road Runner access. I installed a Lexmark X83, and when printing the test page or any document, it takes about10 minutes for it to print. When I disconnected the cable modem from the ethernet card it printed normally. What is wrong? I wrote to Lexmark and Dell, and they said to ask the other “guy”.