Hi Lisa Marie Mary
I'm using 2.7.1 - how interesting ... Have a WP.com article where they say it no longer works since v 2.5. But ... just tried out your link ... downloaded the 3.1 v of Amazon Reloaded and followed the instructions ... whoopee-do ...
However one part is behaving weirdly. The image link works well ... but when add the items text link to embed in the article ... it inserts fine and then when save it saves itself into a little oblong shape and there's no sign of the link in the posting ... have you come across that at all ... I'm real excited at the prospect of finding such a handy gizzmo - which as you say is super easy ... just need that bit to work and then Lift Off!
Oh and which version are you using as see there are two around 2.1 and 3.1?
Many thanks.
Jane