Look at the date code on the label of the Maxtor. Some retailers are selling "refurbished" maxtor 160GB drives that have a date code from May and July of 2007. They are used, and sold at a low price, but noisy and worn out. The noise is typical of these "used" Maxtors. If that date code isn't current with the date you purchased it, you may have a refurbished, old, and worn out Maxtor. We have seen a lot of them in the past 60 days.
Please report back, as I would be curious enough to do more follow-up with Maxtor... I don't think Seagate or Seagate Maxtor would like this to be happening any more than a user with a noisy drive.
Some actually have the name of the person, and refurbishing center, but they are still used and noisy.