Getting AM Radio through your modem? The phone wire is acting as an antenna. Make sure the modem is screwed down to the computer case or the cable is screwed in at both plugs. Some motherboards are not grounded (held by clips) and they should be grounded. Try some tinfoil around the phone wire, and the wire should be as short as possible. Slide the foil up/down the wire to detune it. This usually works, unless the house wiring is picking it up. Then you may need a phone filter (from radio Shack etc).