Here's the screen photos of Cybook Opus and Amazon Kindle. I converted the epub to mobi via calibre. It works. I didn't add any extra fonts with special characters prior to this, just copied epub to Opus without any fiddling and just changed to mobi for kindle. I hope it helps. I did my homework well when I was out to buy ereaders for my tribal language full of those funny letters. Apologies for not good quality of pictures but in this case it doesn't matter