We have a Phaser 7760 that just drops off the network after a few minutes. We have to reboot the printer to get it back on the network. Sometimes even after you send 1 print job it will print it, then you cant print anymore until you reboot the printer. I can still ping the printer IP address, but cant get to the webpage. I did do a network test and got a ND18 error, but I dont see how DNS would cause it to drop off of network. Any suggestions?