Having Yum Problems

Hello,

I am having yum problems with my server. The OS is Centos 4.6,
yum version centos-2.4.3. Yum emits this message during
activation:

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

   librpmbuild-4.4.so: 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, Dec 11 2007, 05:27:57)
[GCC 3.4.6 20060404 (Red Hat 3.4.6-9)] "

Can someone please tell me how to rectify this problem. All help
would be gratefully appreciated.

John Fox.