We've created this Forum Thread with some workarounds and advice to assist you in publishing you ebook.
How much of your paperback do you reveal in your preview? I wanted to offer a decent size preview [ prologue, chapter 1, with front and back covers, within the 2mb limit. I hope I have that correct 2 mb. This is a 398 page novel. The genre's are somewhat limited and I'd like to allow a potential buyer the info to decide if it's what they're looking for.