System registration on satellite server fails with"ExpatError: not well-formed (invalid token)" error.

Issue

• Satellite server generates a traceback email for few systems when they try to update the hardware profile using

# up2date --hardware

• registering system with rhnreg_ks fails with Internal Server Error

# rhnreg_ks --username USER --password PASS --force
An error has occurred: 
Internal Server Error

• system registration on satellite server using bootstrap fails with following error

Traceback (most recent call last):
  File "/usr/share/rhn/server/apacheServer.py", line 58, in __call__
    ret = f(req)
  File "/usr/share/rhn/server/apacheHandler.py", line 198, in handler
    ret = self._req_processor.process()
  File "/usr/share/rhn/server/apacheRequest.py", line 465, in process
    params, method = self.decode(_body)
  File "/usr/share/rhn/server/apacheRequest.py", line 389, in decode
    self.parser.feed(data)
  File "/usr/lib64/python2.4/xmlrpclib.py", line 527, in feed
    self._parser.Parse(data, 0)
ExpatError: not well-formed (invalid token): line 2014, column 47