I had a couple dozen books in my shopping cart on ebooks.noet.com, decided that the total cost wass more than I wanted to spend right now, so I picked a rather expensive book in the middle of the cart and clicked "Remove" beneath it. After a moment the cart updated, and that book I tried to delete was still there. Instead, the first book in my cart was removed. I tried it again and the same thing happened. Kept happening over and over. After a few tries, I decided to record it happening yet again. Here is that recording:
http://www.screencast.com/t/UYspkuhTtOuc
