I've edxported several similar books to EPUB from InDesign CS5, using the same technique each. After exporting from InDesign, there's a lot of tweaking of the HTML code and some changes to the content.opf and toc.ncx, but the finished product for all of the books works fine on iPads but some do not work on Android tablets. There are six separate InDesign documents in each epub book...three small, one large, and then two small. Some of the books work fine on Android tablets, but for some of them, the first three documents show up fine, but when one advances to the large document, the book closes. There's no error message. Any ideas what the problem might be? Are there size limitations for documents on Android machines?