Network adaptor disconnected???

Well, I'm having the strangest problem ever. I am using a 2wire usb to phoneline HPNA wired network adapter to connect to the gateway downstairs. At first, it was working fine, but then started randomly saying "network cable disconnected" without any reason and the internet stayed running fine. I ingnored it, and it began to happen more frequently just recently. Today, it says it indefinitely and the connection isn't working at all. The lights on the adaptor for "network" and "power" are both green, so there really isn't anything I can do. I've tried everything I can think of, which includes resetting the adapter and connection, and restarting the computer, as well as unplugging it and plugging it back in. Any help?? :? :x