Centos – I get dependency error when I try installing YUM on CentOS 5.5

I'm in the process of installing YUM on CentOS 5.5 and following instructionsin this page:
http://wiki.openvz.org/Install_yum

My system is x86_64.

I'm executing the following command:

rpm -Uvh http://mirror.centos.org/centos-5/5.5/os/x86_64/CentOS/rpm-python-4.4.2.3-18.el5.x86_64.rpm

But then I get the following error:

error: Failed dependencies:
popt = 1.10.2.3-18.el5 is needed by rpm-python-4.4.2.3-18.el5.x86_64
rpm = 4.4.2.3-18.el5 is needed by rpm-python-4.4.2.3-18.el5.x86_64
rpm-libs = 4.4.2.3-18.el5 is needed by rpm-python-4.4.2.3-18.el5.x86_64


Any ideas how I can fix this issue?

Doing 'yum clean' gives methis error

There was a problem importing one of the Python modules
required to run yum.
The error leading to this problem was: No module named rpm
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, Sep 3 2009, 15:37:37)
[GCC 4.1.2 20080704 (Red Hat 4.1.2-46)]

Update 2
Running rpm -q rpm rpm-libs popt, it gives me this:

rpm-4.4.2.3-20.el5_5.1
rpm-libs-4.4.2.3-20.el5_5.1
popt-1.10.2.3-20.el5_5.1