Not sure of any solution to your problem - on my clean install of Fedora 13 those commands work 100%.
As per post #2, generally upgrading Fedora from an older version is not something recommended, as usually something will break - even the Fedora Project recommends (see http://fedoraproject.org/wiki/YumUpgradeFaq
) rather backing up your system and doing a clean install.
An upgrade install via yum does work, however, on a more customized install (that is not your typical Fedora installation) you are bound to run into problems.
I recommend you back up everything of importance and re-install your machine.