[Centos] centos 3.3 and updates for 3.1

[centos@xxxxxxxxx (Taco Scargo)]

Seth,

> Updating from 3.1:
> An update from 3.1 should be seamless. Simply, running 'yum update'
> should get all the latest packages from your local mirror repository. Keep
> in mind this is a lot of updates from 3.1 to 3.3. You may need to free
> up some disk space in order to complete this update. This will update
> your centos-release to 3.3. At this point your yum.conf should be
> pointing to the 3.3 path by using the $releasever variable.

Somehow yum update does not find any updates.
I am using the following base url for updates:

baseurl=http://archive.cs.uu.nl/mirror/Linux/cAos/centos-3/$releasever/updates/$basearch/

Thanks,

Taco