[CentOS] Broken up2date & install from CD ?

I've run into some problems I can't explain. I tried to install the mysql package from the 4.1 CD's and the installer just sat there telling me to insert the CD into the drive and click OK. I did that, and it just blinked once, then returned to the same thing.. hit the OK button, etc., etc., again and again. Wound up having to yum install the mysql package which went OK afik. Now, trying to run up2date for the latest updates, and its hung on fetching the obsoletes list for channel centos4-addons. Will not go any further. I had to remove DAG from the repos, as every time I tried to fetch something, it bombed out, so don't know if its my problem or somewhere else.

Hints??

Sam