Losing network connection - on wired network

My WiFi router is just too far from my print server so I hard wired my box onto the network with an Ethernet cable. Everything works great for a while, but after about 5 minutes it drops off the network and never joins again unless I reboot the Pi. At first I thought it might be trying to connect to the WiFi and then dropping so I removed the wireless from the list of networks, but the problem still occurs. If I can get the print to start it goes fine to completion. How do I fix this?

Thanks,
Alex

Can you send us logs