All settings were "AUTO" in /etc/openoffice/openoffice.conf I got to change the following settings to get text back : UI_FONT="Arial" FONT_SCALING="12"
Hmm, FONT_SCALING is expected to get a % value, and 12% is small. ;-) For the font, that won't fit if you don't have Arial, and will fall back to Luxi Sans or some other sans serif font.
