Interesting — I hadn't even thought of using the Amazon plugin anymore, since updating to 5.5!
I'm exporting to ePUB from ID5.5. Then, as you surmised, I'm opening the ePUB in the Kindle Previewer, selecting “view in Kindle Reader,” and letting the previewer run KindleGen to end up with a MOBI file running inside the reader. It's this MOBI file that's giving me problems.
I've not been testing in other readers, because this project was dragging far past its deadline, and Kindle was the only format needed, and the permutations of ID export options, XHTML experiments, and zipped or renamed ebook files were … well … driving me bonkers.
Now you've got me wondering if there's a better workflow. But I'm reluctant NOT to use the ID5.5 export code, in the hopes that they will get it right.
Or perhaps they ARE getting it right, but the KindleGen phase is messing up.
It seems that the ideal (other than having a simple direct path from ID to Kindle that works) would be to use the ID export logic, and then the Kindle import logic, which is basically what I was trying to stick to.
It's wonderfully confusing, here on the bleeding edge, isn't it?
AC