[Yum] yum update CentOS 3.8

[Steve Schilt]

Hello,

I installed CentOS 3.8 this week and would like to run a 'yum update' 
but always get an error that looks like this:

OTHELLO_root /root# yum update
Gathering header information file(s) from server(s)
Server: CentOS-3 - Addons
retrygrab() failed for:
   http://mirror.centos.org/centos/3/addons/i386/headers/header.info
   Executing failover method
failover: out of servers to try
Error getting file 
http://mirror.centos.org/centos/3/addons/i386/headers/header.info
[Errno 4] IOError: <urlopen error >

The yum.conf I am using is the default that is shipped with the 
distro. I have formerly run CentOS 4.4 and  Fedora 4 but did not 
encounter this problem. Any suggestions?

Thanks.