There are a couple of threads that indicate amazon is not working correctly and returning product not found even though the test feature finds asin on amazon. There are at least 2 threads with 2 different patches. It took me a while of reading many threads and trying the various patches to determine which patch is best.
Since it has been 6 months since the patch was offered up on drupal.org, I thought I'd go ahead and open this as a documentation note so that new users can find the patch without having to read all the threads.
The patch is in comment #1 on this thread
the title for that thread is that amazon rejects any product id, although my problem only occurred when the id number started with 1.
Comments
Comment #1
eaton commented#302721: Amazon field rejects any product ID. Amazon API test feature works fine though. is fixed and will be in the next release. Thanks!