No panel apps or control center

[Bill Laundrie <frogking cyberdude com>]

Hi all, I just did a complete reinstall of my RedHat 5.2 system, did all
of the system upgrades, and installed the latest (as of last night) RPMs
for GNOME.  Everything seems to work great EXCEPT I can't seem to be
able to add any new apps to the panel.  I try Panel>Add
applet>Utility>Clock and nothing seems to happen.  With a darker panel
background color, I *CAN* see a little white dot next to the menu icon.

Also, when I try to run the GNOME Control Center, I get the following
errors:

GnomeUI-WARNING **: Could not open help topics file NULL
** WARNING **: Unable reach the control-center.

after a few clicks, the control center window just disappears.

Are these symptoms common to any error I might have made in my install?

-Bill