I’m a little late, but there was a good article fromAngela Eckman Ebensteiner on the Dynamics GP Support and Services Blog on the differences between the Historical Inventory Trial Balance and the Historical Stock Status Report and why the HITB (Historical Inventory Trial Balance) is the one you should be using to determine the value of your stock on a given day and to reconcile with the GL.
If you’re a user of the Inventory Control module, then the article is definitely worth a few minutes of your time.