Bugs in yum update
please stop crying "bug" just because you have a problem! - you did not hit a bug AFAYK - you don't know if the problem is with yum update
Your symptoms make me think that you may have some package not installed. Something unrelated to yum, but related to shell, formatting, output ... Can't tell you what it could be.
I installed a fresh Centos 5.2
that means exactly what?
Kai