I tried to search on this, and didn't find anything, but does anyone else get horrible AM radio interference regardless if the R15 is on or off? If you unplug it, it goes away. I only listen to AM radio for one or two talk shows, and some stations work, but some frequencies are just about unaudible anywhere in the house. It interferes with our attic antenna too, but that's no big deal since the locals are of course on the unit. I was wondering if there was some sort of filter to buy. Thanks!