Partialy responding to myself:
"Alt+F2" then typing "kdesu kate" works well!
If I well understand, the "things" displayed with "root" privileges
are
displayed with "smoothed" fonts. With Kate started as described above,
the characters is well displayed. Hummmm: the characteres displayed in
the TEXTAREA of Firefox 3.6.20 (initial) are well displayed, too.
Sincerly,
Patrick