Got a mtb question for you if dont mind answering it???

right ive got a spesh fsr with a hope disc on the front (dont know which model it is but heres a pic)



the problem ive got is the disc brake squeals like a motha when it gets wet and for about an hour after is there any way of stopping this???

upto now all ive done is taken the pads out and cleaned them and cleaned the disc with disc brake cleaner but its still the same

Any suggestions please fella

simon