[sosuke]

Originally Posted by paulpeer

Thanks for your suggestion! I've embedded the fonts in the ePub now, and this works perfectly for the book itself, but in the Table of Contents the problem remains. Do you have any idea why?

Thanks!

You have to replace the fonts on the reader. The device itself is capable of dealing with unicode the fonts are not. To fix this, see here: https://www.mobileread.com/forums/showthread.php?t=20644