CentOS - Feb 2007 - yum (still)

Hi,

Ok, i've set the proxy, the username and the password in yum.conf

Restarted yum, and now i get:
[root at localhost ~]# yum update
Setting up Update Process
Setting up repositories
Cannot find a valid baseurl for repo: update
Error: Cannot find a valid baseurl for repo: update

I can resolve names (browse the web, etc.)

Any help would be appreciated.

Warm Regards,
M?rio Gamito