Yeah… apparently the ability to restart or shutdown your system using a normal user account from within KDE SC is not something that is installed by default. In order to accomplish this you need to compile and install the kde-misc/kshutdown package using the following command from a root terminal:
I also had to create a new file called /etc/portage/package.accept_keywords in order for this to work. Inside that file just put the following text
Previously I was running KDE 4.3.3 on top of Fedora 11 (for the first experiment) and KDE 4.6.5 on top of Gentoo (for the second experiment).