Re: [CentOS] New on CentOS and update to 4.4

and yum canceld :-( And now...??? Installed is amavisd-new 2.4.2-1.el4.rf

yum is trying to install ---> Package amavisd-new.noarch 0:2.4.2-2.el4.kb set to be updated

I think this is the problem. But what's about a solution

You are mixing similar/same packages from two separate repositories. Pick a repository to use for a specific application, and stay with it. If you use kb then exclude that package from dag/rpmforge. If you want to use it from dag/rpmforge, then exclude it from kb. There are some plugins for yum that can help you do this. The easy solution would be to disable one or both rpmforge/dag and kb repositories whilst you update the base/updates repos.