iPad/Kindle app whispersync question

[jaybee]

I read library books on the kindle apps on my iPad and my iPod Touch. The whispersync function works properly to take me to the last page read. However the documentation says that highlights and annotations are also shared across devices. It's not working for me. I have the latest versions of the app and the "annotations backup" is turned on. My annotations and highlights are saved in each device, but not shared between devices.

Does anyone have an idea what I'm doing wrong or how I can make this work?