DNS broke my Fedora :(

Our local LUG made custom distribution based on Fedora 10 and added extra repositories (livna and rpmfusion). On the day of Installfest we gave our custom distro to everybody who came. People installed it and then we showed them some basic Linux bash cli commands. Everything was working as expected until we came to command called yum. We wanted to show how to install and remove applications under bash command line on distribution-based-on-Fedora but yum failed :(
  After some investigation we saw that for everybody it failed on same thing - livna repository. We concluded that livna repo is dead and disabled it in livna.repo.
  After that yum worked great. Now I have read that livna is not dead but has DNS issues.
  On my home laptop I have both Fedora 9 and Fedora 10. In Fedora 9 I have setup additional Livna repository and I was suspicious when I knew that there were updates for Fedora 9 but update widget didn't show then. Again the same issue. I disabling Livna repository and then update widget woke up and found lots of updates just waiting to be installed.
  I have a question for you: do you think that yum and NetworkManager should be impervious to DNS failure of one repo and just skip that repo or should it fail and stop any attempts for update, install or remove if one repository has some networking issues?
  UPDATE: After updating Fedora 9 and re-enabling Livna repo yum works by skipping it. I'll have to check once more how our custom Fedora 10 is handling this issue and report back... during the Installfest maybe some more issues were the cause of yum failing - local network issues maybe? Anyway, I'll check and report back.