I'm having the same issues with Drupal 5.2, Ubercart alpha8, and Postgres regarding trying to get pricing and shipping information to save. Seems that the "Add To Cart" option doesn't show up because the price never saves. My products just stay at $0.00 regardless of what price I enter. I had posted my issue to the Issue Tracker but haven't had and reply yet.

I realize the Ubercart team might not have a solid Postgres version just yet but I don't know if that is what's causing the issues I'm seeing.