CentOS - Feb 2007 - Problems with yumex after update

Hi Folks,

I've upated yesterday yumex (and other programms).  But now I get an error 
message when starting yumes and yumex stopped.

Message:

[root at main tk]# yumex
Traceback (most recent call last):
  File "/usr/share/yumex/yumexmain.py", line 36, in ?
    from yumex.yum24XBase import *
  File "yum24XBase.py", line 26, in ?
ImportError: No module named repomd

Any hints?
Is repomd a python module? And if so - where can I get it?

Thx
Timothy