yum が動かないときー

There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   No module named cElementTree

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.4.3 (#1, Mar 14 2007, 18:51:08)
[GCC 4.1.1 20070105 (Red Hat 4.1.1-52)]

If you cannot solve this problem yourself, please go to
the yum faq at:
  http://wiki.linux.duke.edu/YumFaq

# rpm -Uvh --force http://ftp.riken.go.jp/pub/Linux/centos/5/os/i386/CentOS/python-elementtree-1.2.6-5.i386.rpm