CM Nethaera posted a small list of know issues with Patch 13.
When attempting to sell an item in the Gold Auction House when you have zero gold, you will get an error. Please get at least 1 gold and try again.
Currently the Diablo III client can be very conservative about how much a commodity is going to cost you. The price displayed when clicking “Buy Out” can be higher than the price quoted during search. If the system is able to find a better deal for you, you will be refunded the difference after you make the purchase. Additional tuning will be performed in the near future.
Sometimes when making a commodity purchase using Beta Bucks, a Gold entry will be viewable in your “Completed Auctions” tab. Attempting to send this Gold to your stash will do nothing. You may need to close the Auction House interface or log out to be able to send items to the stash after attempting this.
Sometimes clicking on the “Send to Stash” button for commodities will gray out the button but not deliver it right away. Please give it some time. You may need to log out and log back in and try again.