a way to ignore "available" updates where a download can't be retrieved ?

Hi,
I use the yum-skip-broken plugin to allow my machine to get at least 
partially update even when the repo's packages have missing /conflicting 
  dependencies.

Is there a way to use yum to achieve a similar effect for when 
particular rpms can not be found in the configured repo's 
{baseurl/mirrorlist} ?

This sometimes happens on some of the real mirrors for Fedora, but more 
regularly when using my internal repo, where the repodata is up2date, 
but specific machines have differing package sets.

So for example, there are ten updates available, and my mirror has 5 of 
them. What could happen is that {assuming no unresolved dependencies}, 5 
  packages would be updated, and the other 5 would be noted as not 
updated due to missing rpms.

DaveT.