I just pulled my DP carbon clutch pack out and replaced it with a Barnett set. The noise has gone along with the clutch grab. The Barnett clutch is much better for road/track usage. The DP carbon clutch in comparison is awesome on the track, but sh*t on the street.

Update on Barnett clutch. The clutch blew while dyno tuning, it did not have enough clamping power for the 999.

I've known several people that found the same as you, mostly on the 916/996 bikes. The were initially smooth but didn't last very long at all.