Chances are that the edge of the rotor is just making contact with the pad, a little grinding off of the pad near the edge of the rotr would stop it.
I referance to the KVR's I have the setup, and love it! The KVR Carbon Fiber pads are semi-metallic too, but way more rotor friendly. Watch your speed when new though! VERY SLIPPERY during break in, and after you have had them for a bit you will see that it takes them a second or two to warm up and really bite, but when they do! Oh Boy! they are awesome. Recommend it I do!!
