ZZR1100 brake squeal

I have just bought a second hand 1999 ZZR1100. I noticed the front brakes squealing under light braking on the test run. I asked the dealer, (very reliable guy), about it and he told me he had just installed metallic composite front pads and the squeal will go shortly. I have only ridden about 400k on the bike but noise is still there. This only happens under very light braking and not under heavy load. I have sussed out the rotors and there is no scoring to indicate a rubbing problem. Any suggestions?