Hot off the presses, version 5.1.2 is out! This version deals mostly with bug fixes and and plug-in improvements but it also includes a small change to the Amazon sign up to conform to the new Amazon API rule changes which will come into effect on August 31st. All users now have to sign up for their own Amazon associates ID, you can no longer use the default Bruji one provided, since Amazon now requires that the security credentials (access key and secret key) and the associate ID are registered to the same email address. So if you haven't done so yet, sign up for an associate account on Amazon's Associate Program site if you want to keep on using their search.
We've put up a blog post with more details about how to sign up and links to Amazon's forum if you'd like more information about the changes.