转自：http://zhangjunli177.blog.163.com/blog/static/1386073082012103052527557/
VNC viewer desktop dead lock after click the system menu
Have the following problem with vnc in RHEL5.5:-
When click the "System" menu in the vnc desktop, the VNC desktop is dead locked. To let the vnc work, need to restart the vncserver or kill the process gnome-panel w/o restart the vncserver.
But that will not fix the problem thoroughly as the vnc desktop will be dead when click the "System" menu again.
The reason for the problem is monitor not connect to VGA card. To fix the problem, can use one of the following to method:-
(1). connect monitor to VGA card :-)
(2). if option1 is not applicable to you case, you need change the run level from 5 to 3 by edit the file
/etc/inittab
id:3:initdefault:
refer to http://bugs.centos.org/view.php?id=3796