ubuntu 8.04 yum 이 실행이 되지 않네요.

yum 명령을 실행하면 다음 메시지가 뜹니다.

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:
2.5.2 (r252:60911, Jul 31 2008, 17:28:52)
[GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)]

If you cannot solve this problem yourself, please send this
message to .

여러가지 방법을 알아보고 혹시나 싶어 python2.5.1과 2.4.5를 다운받아 깔아보고 했는데 여전히 안되네요.

도와주세요