buzzy (sharp) static-like noise (m1330)

It was a real pleasure to receive my new Dell laptop M1330 yesterday just after two days I put the order.

But now I am suffering the continuous static-like, high frequency noise and it's too loud to stand.

Everytime when the Vista Logon screen shows up, the noise comes up and it doesn't stop until I shut computer down or put the computer into sleep mode. 

This afternoon, I called Dell XPS hardware support. After listened to the soft music on the phone for over one hour, I gave it up.

I suspect there is something wrong related to the hard-drive which is a Seagate 160G 5400rpm SATA. But no spare 2.5" hard disk on hand, so it's impossible to try to swap another model to see what gonna happen.

What should I do if the problem with EMI (electro-magnetic interference) is true? Can I send this laptop back to Dell and ask for a refund, or get another one?

Appreciate anyone could help. Thank you.