yum-error

hi guys (and girls, of course),

doint yum check-update, i got the following:

[root@link roger]# yum check-update
Traceback (most recent call last):
  File "/usr/bin/yum", line 22, in ?
    import yummain
  File "/usr/share/yum/yummain.py", line 31, in ?
    import yumcomps
  File "/usr/share/yum/yumcomps.py", line 4, in ?
    import comps
  File "/usr/share/yum/comps.py", line 5, in ?
    import libxml2
  File "/usr/lib/python2.3/site-packages/libxml2.py", line 1, in ?
    import libxml2mod
ImportError: /usr/lib/python2.3/site-packages/libxml2mod.so: undefined symbol: xmlNewDocPI


whats up with yum?

Roger