Hi. Sorry for getting back to the discussion with such a lenghty delay.
I attampted covering that hole, but tis didn't solve the problem.
dghii seems to be right by suggesting the the noise seems to be connected with the radio operation.
The thing is the noise is there only while the radio is OFF, as soon as I put it on, it goes away. Weird, innit?! I guess I need to have it checked... or just continue listening to my favourite tunes at all times. :ah: