Desktop Fonts less than 16pt -> no Antialiasing

This is with KDE 3.5 on OpenSuse 10.0. Enabling Antialiasing in KDE Control Center has no effect on all fonts when setting them to less than 16pt. I am not sure whether this is a KDE related problem. Could also result from a rather unusual screen setting (1024x600) which X appears to have some problems with (i.e. I successfully edited the x.org configuration file in /etc/x11 which, however, now can't be opened by Sax). Anyway, maybe someone can shed some light on this. Thanks! Guido