[root@andrew ~]# 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
  File "__init__.py", line 22, in ?
  File "/usr/lib/python2.3/re.py", line 5, in ?
    from sre import *
  File "/usr/lib/python2.3/sre.py", line 98, in ?
    import sre_parse
ValueError: bad marshal data
[root@andrew ~]#