The suspend and hibernate features of Linux can be unreliable. To prevent this feature from being used accidentally, the suspend and hibernate buttons can be disabled in Gnome.
# yum -y install gconf-editor
Applications->System Tools->Configuration Editor
apps->gnome-power-manager->general
apps->gnome-power-manager
can_hibernate
can_suspend
The next time Shut Down is selected from the menu, these options will no longer be present.