when I turn down the gain about half way it will not happen but thats disappointing because I usually play with the distortion cranked, and I should be able to have full range. I did a little more investigating with a keeley ds-1 I just got, and it does the same thing, but its only faint, and gets worse as I move my srumming towards the bridge pickup. I also have a silver screw ds-1, and again its very faint(less than the rat and the keeley).
Now.......a friend of mine brought over a ds-2, and it didn't happen at all...Im stumped