[Nav-users] Modules up and down

Hi. I have two Cisco 7206 routers in my network. According to Nav the modules in these routers continuously goes up and down. Each module is almost always declared as down in 5 hours, then it's declared as up again for one hour, before it's declared as down again.. Of course the modules are up all the time. I have tried to delete the routers from Nav and add them again, I have tried different ip-addresses (yes, the loopback address to) without any success. Any suggestion anyone ? - odd arne hauge