Have you tried RF Stoppers (ferrite clamp) by Audioquest? These little magnet cylinders clamp onto your interconnect and block FM noise. Radio Shack also made a version. The Cable Company web site has the RF Stoppers for sale:
http://www.fatwyre.com/FATWYRE/fatwyre/accessories.html
(Scroll down to "Miscellaneous" which is not quite halfway down the page.)
http://www.fatwyre.com/FATWYRE/fatwyre/accessories.html
(Scroll down to "Miscellaneous" which is not quite halfway down the page.)