VNC and black screen on relogin

[redhatdude at bellsouth.net]

Hello,
I set up vncserver and I can connect without problems. The problems  
start when I log out of KDE and the screen goes black. I quit the vnc  
viewer and when I try to log back in all I get is the black screen.
How can I get X to run the next time I log in with vnc without having  
to restart the vncserver?

This is my xstartup, without the first two lines uncommented I also  
get a black screen.
How can also get an xterm instead of KDE right after I log in?

unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc

[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
twm &


Thanks,
EJ