Second Generation Kindle Fire (2012), System Version: 10.5.1
Moon+ Reader Free 4.2.2
As it turns out, Calibre has the ability to split files bigger than a given size so I tried setting it to 21K (instead of the default 260K). Unfortunately that didn't help. Apparently the size threshold is not really the size of the File but of the Chapter, and Moon+ Reader must combine the split files back together.
It seems that any sort of character style causes the current horizontal position to be reset back to zero, thus causing overlapping. Changing from italics to underline or bold also results in the same error.
Anyway, I have given up on using Moon+ Reader, especially since there doesn't seem to be any official way of reporting bugs to the developer other than sending an email? Does anyone know if they actually follow the forums here on mobileread? BTW, this thread is probably in the wrong forum since the problem doesn't have anything to do with Calibre.
I have switched instead to
FBReader (
for Android) which can handle epubs just fine and doesn't show any of the problems that Moon+ Reader has with italics. It's also open sourced
on GitHub, so there is an official way to report issues and I can always look at the code if I want to.