AD3208 making funny sounds

[ohmen]

I was the one who reported about the "fried" AD3208 some weeks back. I received all the IC's from Smallbear on Saturday and it's now up and running again. Turns out only the SA571 was "fried". I now have and extra set of working MN3205 chips.
The delay is working fine, but every now and then when I switch on the effect, it starts making high pitched sounds. These sounds change in pitch if I turn the knobs or if I move the cables around. They do not go away though before I remove the power source and connect it again. Does anyone have a clue on what this is?