Just to be clear (people won't always follow links around here), this eats the warning messages by activating the CG error-handler.php code -- it installs a custom error handler, that buffers error messages rather than having them echo out to the page. You can call myErrorOutput() in the footer.php file or something, preferably only for admin users!, if you want to see the error messages when/if they show up.
This does NOT solve the actual warnings being generated, or any issues therein -- it just hides them so you, and your users, don't see them. I'm still working on the proper fixes to eliminate those warnings, but it does still seem that CG-Amazon is completely functional despite the warnings.
Hope that helps,