I'm seeking a new maintainer for this project. I do not have the time to commit to regularly merging changes back into this module.
If you are using the Commerce Shipping 7.x-2.x Module/API you should use the Commerce USPS module instead. See http://drupal.org/project/commerce_usps.
This module provides a USPS shipping method for the Commerce Shipping module. Currently the Product Type must have a field_weight for it to work. In the future I hope to abstract this better.