Two problems with shipping. Both issues persisted with all other plugins deactivated.
Firstly - When purchasing 3, 6, 7, 8, 11, 12, or 13 items (I did not test past 14 as it was pretty disheartening), user cannot calculate shipping. 1 item, 2 items, 4 items? Everything works perfectly fine. This is clearly a huge problem, as many of my customers would like to purchase 3, 6, 7, 8, 11, 12, or 13 items. I had this issue before. It was a bug in WP E-commerce, and the next roll out fixed it.
Secondly - Shipping to other countries apparently doesn't work, when it did previously. All target markets are selected, without apparent effect. I have to hope international customers e-mail me so I can set them up with a workaround that "ignores" shipping, or send a paypal invoice. This complicates my bookkeeping, takes up more time, and loses sales as well.