Python/up2date error on RHEL4

[Dayton Jones]

I'm trying to run up2date and keep getting:

Traceback (most recent call last):
   File "/usr/sbin/up2date", line 27, in ?
     from up2date_client import repoDirector
   File "/usr/share/rhn/up2date_client/repoDirector.py", line 5, in ?
     import rhnChannel
   File "/usr/share/rhn/up2date_client/rhnChannel.py", line 10, in ?
     import up2dateAuth
   File "/usr/share/rhn/up2date_client/up2dateAuth.py", line 5, in ?
     import rpcServer
   File "/usr/share/rhn/up2date_client/rpcServer.py", line 23, in ?
     from rhn import rpclib
   File "/usr/lib/python2.3/site-packages/rhn/__init__.py", line 11, in ?
     import rpclib
   File "/usr/lib/python2.3/site-packages/rhn/rpclib.py", line 14, in ?
     import transports
   File "/usr/lib/python2.3/site-packages/rhn/transports.py", line 24, in ?
     import connections
   File "/usr/lib/python2.3/site-packages/rhn/connections.py", line 14, in ?
     import SSL
   File "/usr/lib/python2.3/site-packages/rhn/SSL.py", line 15, in ?
     from OpenSSL import SSL, crypto
   File "/usr/lib/python2.3/site-packages/OpenSSL/__init__.py", line 11, 
in ?
     import rand, crypto, SSL, tsafe
   File "/usr/lib/python2.3/site-packages/OpenSSL/tsafe.py", line 5, in ?
     import threading
   File "/usr/lib/python2.3/threading.py", line 11, in ?
     from StringIO import StringIO as _StringIO
ValueError: bad marshal data


When trying to launch the rhn-applet I get:

Traceback (most recent call last):
   File "/usr/bin/rhn-applet-gui", line 30, in ?
     import rhn_applet
   File "/usr/share/rhn/rhn_applet/rhn_applet.py", line 31, in ?
     from StringIO import StringIO
ValueError: bad marshal data



What exactly is "bad marshal data"  How can I resolve this?

Red Hat Enterprise Linux ES release 4 (Nahant Update 2)


Thanks in advance