WP e-Commerce stock control

I have followed the documentation for using the stock control and are having issues with the following:

1. The stock levels are not updating.
2. The stock levels are not seen by my customer on my site.
3. I am not receiving email notifications when stock levels are depleted.
4. When the “Unpublish this Product if stock runs out” box is checked the item is still showing on my site. It does however say “Product not in stock” & “This product has sold out.”

Having inventory levels updated is very important. Am I missing something here? why does this not work the way it should? any suggestions on how to get my inventory to update properly and to have it shown on my site so it is seen by the customer?