What is this annoying creaking noise when S90 turned on?

Guys and gals,

I don't know what's been going on in this S90.
Mine I just opend up today and palying with it around my work desk.
Indoor photos are fantastic. Couldn't ask for more!

But one thing Ikeep hearing is this creaking sound from the body when I turned it on.
Has somebody addressed this unidentifiable sound issue before?

Otherwise, I might return it to the Best Buy and to see if others do have same funny sound issue.

Thanks for your inputs.

Sunny