ok, i bought a Gen 3 15Gig iPod about 15 days ago, i run with it occasionally, 3 times a week for an hour. didn't notice it before, but when i shake it very lightly and listen closely, it sounds like something inside is moving, like a click noise. Is this normal? When it spins up, i dont think you can hear it...not sure if this has something to do with the hard drive or what...any help would be greatly appreciated.

P.S. sorry if this issue was posted somewhere else, couldnt find it.