Error: Cannot retrieve repository metadata (repomd.xml) for repository: boxgrinder-noarch

Error: Cannot retrieve repository metadata (repomd.xml) for repository:
boxgrinder-noarch

I am trying to run yum update on my machine and I get this error.
Error: Cannot retrieve repository metadata (repomd.xml) for repository:
boxgrinder-noarch. Please verify its path and try again
Any idea what is wrong?
I use Fedora 15