Dunno...Here's what I'd do:
I'd stop using the bike until the problem's solved and fixed.
Check the oil level to see if the clutch is too far out of the oil bath (unlikely).
Does the clutch noise happen at all idling speeds? If it's at only one speed, it's just a sympathetic vibration and that's harmless. My Busa does that in a microscopic rev range.
Have you had clutch slipping problems after repeated severe launches? If so, you may have developed plate wear and spring problems.
Have you been cleaning and lubing your chain often enough?
MY DIAGNOSIS: Sounds like your chain has been way too tight, and that could cause a lot of drive train problems...right through to the clutch. Don't set it by passive sag. On the side stand, put a tape measure beside the lower portion of the chain at mid-point and actively lift the chain upward. Your travel must be between .8 inch and 1.2 inches. If you've had it as low as .25 inch, that's trouble for sure.
If you've had the chain way too tight all along and have been using it hard, it's probably internally damaged and this may be your "popping" noise.
If it turns out your chain has been kept too tight, have a mechanic replace the chain and inspect for collateral drive train damage.
[This message has been edited by Dirty Pete (edited 26 August 1999).]
