hi Guys,
my 02 XX has this very same sound and has done since I bought it with 4000 miles on the clock, it now has 34,000 miles and the noise is still there, no better no worse. My earlier 96 XX had the same noise. It only really happens when the bikes really warm and siting in traffic. My mate has an 05 model with 13,000 miles on it now, and thats done it ever since it was run in.
I dont think its the CCT, I've one of those go and it was a completely different type of noise. I don't think its the big ends, little end, mains or c/b shafts. I had sort of convinced my self it was more a piston slap issue, and as long as it doesn't get any worse its fine.
I also think that the majority of XX's do this and a lot of it is down to the rider as to whether he hears or feels it and actually pics up on it at all.
Stu