Tappet noise?

I've had my 2002 ZX6-R (J1) for nearly two weeks now and I notice a gentle tappet-like noise, particularly around 4,000rpm when the throttles closes (to cut down the exhaust note).
The bike is not even two years old yet, has 2,500 miles on the clock and has been looked after. It's only had the 500 mile service.
Is this noise normal? I guess I'm just being paranoid!




Silver/Black ZX6-R (2000 J1)

"Come on you R's!"

(That's 'Queens Park Rangers', an English football (soccer) club!)