The following on-board fonts are preventing the display of the characters in question: Avenir, Amasis, Caecilia, Georgia, KBJ-UDKakugoPr6N-M. This leaves in the directory of on-board fonts on my device the following files:
Code:
[root@(none) ~]# ls usr/local/Trolltech/QtEmbedded-4.6.2-arm/lib/fonts
GillSans-Bold.ttf Malabar-Bold.ttf
GillSans-BoldItalic.ttf Malabar-BoldItalic.ttf
GillSans-Italic.ttf Malabar-Italic.ttf
GillSans.ttf Malabar.ttf
Gothic MB101.otf OpenDyslexic-Bold.otf
KBJ-TsukuMinPr6N-RB.ttf OpenDyslexic-BoldItalic.otf
KoboNickel-Bold.ttf OpenDyslexic-Italic.otf
KoboNickel-BoldItalic.ttf OpenDyslexic-Regular.otf
KoboNickel-Italic.ttf Ryumin.otf
KoboNickel.ttf
Note that Gothic MB101.otf and Ryumin.otf are empty files.
The important file is KBJ-TsukuMinPr6N-RB.ttf. Without it there would be no font left that the GUI can use before a book is opened. Curiously, the GUI does not display Japanese characters, even after opening a book. (It does however still display Japanese characters in books.)