Found the solution from a ubuntu chap
http://www.watchingthenet.com/restor...#comment-16009
Basically open a xterm or a terminal.
Issue the following command to restore the original panels:
[ckgan@centos52-64-dell ~]$ gconftool-2 --shutdown
[ckgan@centos52-64-dell ~]$ rm -rf ~/.gconf/apps/panel
[ckgan@centos52-64-dell ~]$ pkill gnome-panel
This is a life saver!