Yum Error on CentOS 4.5

[Al Sparks]

Running CentOS 4.5

Whenever I do a 
   $ yum update

I get:

  http://linux.dell.com/repo/software/el4/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found  Trying other mirror.
  Cannot open/read repomd.xml file for repository: dell-software
  failure: repodata/repomd.xml from dell-software: [Errno 256] No more mirrors to try.
  Error: failure: repodata/repomd.xml from dell-software: [Errno 256] No more mirrors to try.

That's very annoying, because I can't use yum at all for ANY updates, not just Dell.

Any hints to fix this?
   === Al