Good news! Weiser has a lifetime warranty against mechanical defects and problems with the finish (but only a one year warranty protecting the internal electronics). Here's the link to the warranty page:

http://www.weiserlock.com/CustomerService/WarrantyInfo/Powerbolt.aspx

But before you pursue that, a few questions and comments. How does the lock function with the door open? If it functions okay, then you need to investigate the alignment between the door lock and the door jamb/strike plate. Also, these locks can be internally adjusted for installation in doors with a 2 3/8" or 2 3/4" backset. Is it off by about 3/8"? if so, check that.
Some months ago I suggested that possibility to someone else with much the same problem. He found that a plastic member had disintegrated in that area of the lock and was jamming it up.
Here's a link to the installation instructions; you'll see what I'm talking about under Item 2 Deadbolt Latch Installation (Piece B)

http://www.weiserlock.com/Support/Faq/50160000000HhmZAAS.aspx

A note about PDF files: If you cannot view the installation instructions, you need to first install Adobe Reader. You can get the free download here:
http://get.adobe.com/reader/
http://www.weiserlock.com/Support/Faq/50160000000HhmZAAS.aspx

Good luck--and please leave feedback if this helps!