What is the background ? Have you only just installed ? Is this a new error, or has it never worked ?
What files are listed in /etc/yum.repos.d ?
There should be a fedora.repo and a fedora-updates.repo at the least.
If they are there, what is their contents ?
Alternatively, open System > Administration > Add/Remove Software and using the System menu, choose Software Sources. This will list your repos, with a check mark beside the active ones. If you have the two repos I mentioned above, make sure they are checked but no others.
Last edited by smoker; 07-08-2010 at 12:08 PM.