Are all your links to images present in your INDD file? Are you exporting to EPUB3? Are you careful to style your text with paragraph styles? Have you gotten rid of as much directly-applied text formatting that you can? Are you using a web-based EPUB validator to check out what is wrong with your EPUB?
Yes, I've done all the things you recommand, except the validator EPUB.
I've got some images, because it's a book destinated to children. So I've also verified that my blocks don't have any wraping form.
Since, when I convert INDD in EPUB3, it says that : " non-rectangular objects do not display when exported with CSS" (but I don't find any non-rectangular objects in my document, except if my PNG files are considered like non-rectangular objects), and then, my EPUB document can't be open like Adobe Digital Edition says there are somme errors so that we can't open the document.