[root@asterisk0 ~]# yum clean
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   libelf.so.1: cannot open shared object file: No such file or directory

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:
2.3.4 (#1, Feb 22 2005, 04:09:37) 
[GCC 3.4.3 20041212 (Red Hat 3.4.3-9.EL4)]

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

[root@asterisk0 ~]#