ethernet printer will not print unless internet is disconnected

Here's a strange one.

MacBook OSX 10.4.10
10 Base-T ethernet hub
Cable modem internet connection into ethernet hub
Epson 3000 running with latest Gutenprint, CUPS, PPD, with properly assigned IP address, connected to hub

I cannot print unless I disconnect the internet ethernet cable. If the internet cable is connected, when I try to print, the print window shows that the system is searching for the printer IP address, but it never finds it.

So I cancel printing, unplug everything from the ethernet hub, and plug back in only the computer and the printer, print again, and bam it finds it immediately and prints.

I plug the internet back in, try to print something else, and it does not find the printer again.

So I have to unplug the internet to print? What in the #*&@ is going on here?

Thanks,
Aaron Hunt
H-Pi Instruments