VNC server under Suse 9

I tried to use vncserver on Suse 9, but to my surprise upon starting up with "vncserver" and then connecting with the "vncviewer" command I only saw the grey screen and an X terminal. I tried to execute xclock and gaim and they start up nicely. However I would also like to bee able to start up KDE. So I looked into the xstartup file (in the .vnc directory in your home folder) from my old Red Hat 9 install and compared it to the one from my Suse 9 install:

Suse 9:
!/bin/sh
xrdb $HOME/.Xresources
xsetroot -solid grey
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
twm &

Red Hat 9:
!/bin/sh
Red Hat Linux VNC session startup script
unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc

I figured out that twm is a window manager; thus it replaces KDE in this context. If I replace the Suse script by the Red Hat script, KDE starts up upon starting vncserver.