I tested the 20090316 release of kubuntu and I'm still seeing this problem.
Based off comment #37 from mvirus, I tried upgrading ubiquity* to version 1.11.18 and that didn't help. I then tried removing ubiquity-frontend-kde/1.11.18 and replacing it with ubiquity-frontend-gtk/1.11.18 (this required installing other packages like the gtk version of apport). When using the gtk-based ubiquity I was able to complete an install (and the timezone selection screened rendered properly too!)
I tested the 20090316 release of kubuntu and I'm still seeing this problem.
Based off comment #37 from mvirus, I tried upgrading ubiquity* to version 1.11.18 and that didn't help. I then tried removing ubiquity- frontend- kde/1.11. 18 and replacing it with ubiquity- frontend- gtk/1.11. 18 (this required installing other packages like the gtk version of apport). When using the gtk-based ubiquity I was able to complete an install (and the timezone selection screened rendered properly too!)