- $chapter = $content_start.$entry->getContent().$bookEnd;
- $book->addChapter($entry->getTitle(), htmlspecialchars($entry->getTitle()).'.html', $chapter, true, EPub::EXTERNAL_REF_ADD);
+ // the reader in Kobo Devices doesn't likes special caracters
+ // in filenames, we limit to A-z/0-9
+ $filename = preg_replace('/[^A-Za-z0-9\-]/', '', $entry->getTitle());
+
+ $chapter = $content_start . $entry->getContent() . $bookEnd;
+ $book->addChapter($entry->getTitle(), htmlspecialchars($filename) . '.html', $chapter, true, EPub::EXTERNAL_REF_ADD);