Man, oh brother. I've been watching this thread and alternately scratching my head and picking myself up off the floor.
The idea of getting somebody over there with an RF meter doesn't sound too far beyond the pale of reason.
Another thought that occurred to me is that these infernal bit boxes induce "back EMF" or a reverse voltage into the power lines. Trying a UPS with everything computerish plugged into it may give you a clue, as the machine may be radiating RF back through the power line, and if it happens to hit the right frequency in Linux, well, who knows? A UPS is like the electrical equivalent of a water balloon and the back voltage an interference wouldn't make it back out the supply side.
As for the Linux only thing...... (Walks around the room scratching his head and falling down for a few minutes)
Linux is a fast OS and Windoze is chock fulla bloatware, right? Maybe Linux is executing instructions at a faster rate, somehow, causing something else in the system to operate more quickly, thus causing the internal frequencies (and subsequent RF) to change, creating the Linux-only phenomenon? Heck, I don't know, I'm groping
Glad it's not your garage door opener, though