Sometimes the Gnome menu gets all weird (at least for my setup).  Just add the following script into /usr/local/bin, make sure you can execute it (chmod +x resetgpanel).  Run it from the command line, or create a shortcut on the panel itself.

[START CODE]

#!/bin/bash
if ps ax | grep -v grep | grep gnome-panel > /dev/null
then
gnome-panel –replace > /dev/null 2>&1 &
echo “Gnome Panel Reset”
else
gnome-panel > /dev/null 2>&1 &
echo “Gnome Panel Reset”
fi

[END CODE]