Ever since changing to the Black diamond discs, I had a clonking noise from the OSF when going over bumps. Even after kieran and I rebuilt the brakes, it was still there and I thought it was something in the suspension.
However, after having changed the discs the other day, it has gone! I was trying to provoke it today, but it's just gone! Woohoo!
I remember Strangebat had a similar issue with black diamond discs on his VR4. Perhaps Black Diamond are not really worth getting...
Also, the occasional cracking noises have gone completely now that I have a FULL set of anti-rattle shims (both inboard and outboard rather than just outboard, which came after having none at all).