yum upgrade

Hi everyone,

I'm following these instructions:

http://www.brandonhutchinson.com/Upgrading_Red_Hat_Linux_with_yum.html

and have got as far as the step where you start the upgrade process.
However, I've hit this problem:

[root@az bin]# yum upgrade
Traceback (most recent call last):
  File "/usr/bin/yum", line 6, in ?
    import yummain
  File "/usr/share/yum-cli/yummain.py", line 23, in ?
    import yum
ImportError: No module named yum

Any ideas?

Thanks,

James.

-- 
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.8.8 - Release Date: 14/02/2005