Question : Problem: HP Epson Printer communication conflicting

I have a HP LaserJet 4000TN on my network.  I have Epson CX7800 on PC's USB port.  In printing photos (photos only, no other doc type causes problem.  non-photo jpgs print fine too.  photo jpgs are less 500kb.), the Epson would skip the top section and print only the lower portion.  The portions skipped/printed would vary after each sheet - not consistently the same size skipped.

After an hour with 2nd level Epson tech support, it seem if I disconnect my network cable, the Epson prints the photos full page.  (reinstalling Epson drivers didn't solve it).

Unfortunately, I want to share my Epson on the network (save money of course).  I don't really want to be restricted to printing only from my PC with my network cable disconnected or run around and turn off the HP when I photo print.

Epson says its an communication conflict btx my Epson and my HP, even though the HP is via my network cable.   I don't think I have bi-directional set on the HP.   Again, the "conflict" only occurs to photo printing.  Espon says it is not a software issue.  I photo print with Microsoft's Photo Print Wizard and Epson's bundled ArcSoft PhotoImpressions.  Same results.  I can use the same software and print non-photo jpgs just fine.

Is there any better solution?

Answer : Problem: HP Epson Printer communication conflicting

It is almost certainly the IRQ conflict between the nic and the usb controller that is causing the problem.
You may be able to change the irq steering settings in the bios, or maybe not, sorry.