I have a new MacBook Pro with CS5. Since I am previously a PC user, I prefer to have the application frame open all the time. In Photoshop and Illustrator I was able to turn it on, size it, and the settings saved. With InDesign, however, I was able to turn it on but the size never saves--this is driving me crazy!! Any help anyone can give is very much appreciated.
It's supposed to save. Try trashing you preferences first.
Please confirm that you open CS5, set the App Frame on, Quit InDesign, re-open InDesign, and the App Frame is not on?
Have you updated to the latest patch?