Zaon MRX causing radio interference

With my new Zaon MRX PCAS mounted on top of my glare shield, I've been
experiencing some radio interference and linked this to the MRX: the
radio gives white-noise static -- like the squelch is not properly
adusted. When I turn the MRX off it goes away.

I've heard putting a "ferrite core" around the MRX's (and the
radio's?) power cord might help. (Here's one:
http://cgi.ebay.ca/Noise-Filter-Clip...QQcmdZViewItem
).

Does anybody else have this problem? Have you solved it in some way?

Thanks,

Eric
DG-300