I’ve been getting this, too. Comments overall are turned off and the comment for the specific post is off and I’m still getting one or two a day to moderate.
Turns out John, the creator of the plugin, has posted a fix that works.
Go here:
http://dev.wp-plugins.org/file/wp-amazon/trunks/wp-admin/wp-amazon.php?rev=805
Copy and paste the code on this page over the wp-amazon.php that comes in the zip. Just completely replace it and upload it.
Worked like a charm for me. Thanks, John.
Any insight on this one? I get the same problem. The popup comes up empty. Worked ok on 1.2 and I just upgraded to 1.5 and am trying to re-install.
Thanks.