When formatting is input into a book (using the § character), if the formatting continues onto the next line it gets lost whenever the book is actually signed. If the book is still a book and quill, it still displays correctly even if you close and re-enter the book and quill. It is only after it is signed that it displays incorrectly.

The formatting is NOT being lost in the datatags from the convert from book and quill -> written book. I ran /entitydata @e[type=Item,c=1] {} with them dropped on the ground, and the attached .txt files are the results. In there "I am not a killer!" is still wrapped in formatting codes.

Visually, you can see it lose the formatting on "I am not a killer!" (killer! becomes un-italicized), and pretty much the whole second paragraph.

The book displayed correctly in 14w21b, which is the version the map I'm updating was released for (which is what this book page comes from).

EDIT: Using json also doesn't keep formatting correctly. Using the command in command-written_book.txt (attached), the formatting doesn't STOP for the italics until the newline. The "I am not a killer!" 's italic formatting continues on to the next "Please". Looking at the entitydata for the item, I can see why this may be the case. It didn't keep the italic:false explicitly in there, and the formatting seems to bleed into the next characters.

I seem to remember something like this for /tellraws as well, and both can be fixed by giving the next block of text some tag that doesn't actually change the formatting of the text. In this case, I added a color:black tag to the "Please..." block and it fixed it.