iBooks won't keep iTunes categories
I have my books sorted on iTunes, using categories and sort order. On my iPad, however, iBooks doesn't do this. It takes the category assigned when the book is first synced, and won't let me change it. For example, let's say I buy an iBook that I consider Sci-Fi and Fantasy, but the tag it comes with is Fiction and Literature. I can change that in iTunes, I can even give it a useful sort order; iBooks keeps it in Fiction and Literature.
I even tried deleting all the eBooks on my iPad, then reinstalling them (after they were in the correct order in iTunes). After reinstalling, they were in the same order as before they were erased. Some even kept categories that I had deleted in iTunes.
How can I get iBooks to follow the iTunes categories (and, if possible, the sort order)?