Porteus V4.0 X86_64
Seems like some fonts in window titles lose characters sometimes. Mostly "u" and some others depending on the title.
Might be the i915 driver, my font / appearance settings or something.
The easiest fix however seems to just use "slight" or some other form of font hinting:
Settings > Appearance > Fonts > Rendering > Hinting: slight
works for me ....
Slight Hinting for window titles
Slight Hinting for window titles
That's a UNIX book - cool. -Garth