I am unable to get this Amazon widget to display properly and have asked Amazon to get a sorry can't help answer!
After entering the codes and 'secret' code, creating the showcase and putting it in the sidebar the following is seen instead of the showcase.

Warning: implode() [function.implode]: Invalid arguments passed in D:\Hosting\4619720\html\wordpress\wp-content\plugins\amazon-showcase-wordpress-widget\amazonshowcase.php on line 1102

This can be seen in the left sidebar at present http://fastyacht.net/wordpress

I also have still not been able to solve the font color problem in the thread "Unable to change font color of Tubepress widget text" if anyone can shed some light on that too?

so what do you have in the widget that is there?