RF Interference - radio signal through my Transparent Cables.

I own a Woo Audio WES headphone amp connected to a DAC using a 1M Transparent Reference MM1 XLR balanced interconnect.  The Amp is dead silent when the interconnects are disconnected - but I'm picking up a radio station through the cables.  I would have expected balanced Transparent Reference cables to not act as an antenna  - any ideas on how to fix this problem. (BTW, I have the DAC and Amp powered through a PS Audio P600 Power Regenerator).  

Thanks,

Adam