I have a little problem here, not too serious but annoying all the same. I hope you guys can help me... Whenever my knuckles brush against the pickguard, for example when I'm slapping, there is a crackling sound like a static electricity discharge between my hand and the bass (pickguard). Even if I mute the strings with my left hand and rub the fingers of my right hand over the pickguard, the noise comes out over the amp. And only when I touch the pickguard... I had the same problem years ago with my Ibanez Expressionist, but I got around that by cutting out a piece of clear hard plastic to fit on the pickguard as a extra insulating layer. Worked fine, just looked a bit weird. Well, I'm not going to do that with this Fender Marcus Miller Jazz (pickguard already looks weird enough!). Does anyone know what causes this noise and how to fix it? Is it the preamp or the pickups, the wiring maybe?