External Fw Hd And Noise, my HD makes my speakers noisy Options

[MrD.]

hi all ,
for a couple of month now (sinwe we moved) I've expirencing a wierd noise xoming out of my speakers (even when my mixing table is muted - as long as the amp is on) I've finally discovered the reason . My external FW drive.
I've decided to move it to another wall socket, and all of a sudden quite.. but not for long. The next day, when I turn on my studio again same noise.
Again I move it and again its gone, until next time.

So it seems that if I dissconect it while the studio is on, the reconect it nd remount it its quite, oterwise its noisy

Any ideas?