Should you pay mortgage points to lower your rate?

A recent study says mortgage borrowers tend to purchase too many points when selecting a mortgage and end up paying more than they would with no points. Here's a link to Penn State's press release on the study (one of the co-author's is a PSU prof). For the life of me I can't find the full study posted anywhere...don't these people know about the power of the blogsphere?

The critical finding seemed to be that most people sold or refinanced their mortgages too quickly to take advantage of the initial interest rate buy-down.