Description of problem:
When I select Software Updater from the System Tools menu, the software showed
that I have a list of new update. I clicked update and the system generated
exception and suggest me to file a bug against the software updater module.

Version-Release number of selected component (if applicable):
RHEL 5 desktop

How reproducible:
Click System Tools--> Software updater and follow the steps required for update.
  
Actual results:
The first time I ran, this exception message occurred:
Component: Software Updater
Summary: TBe634e670 __init__.py:767:downloadHeader:RepoError: failed to retrieve
getPackage/gnupg-1.4.5-13.i386.rpm from rhel-i386-client-5
error was [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>

Traceback (most recent call last):
  File "/usr/sbin/pup", line 438, in _apply
    self.applyChanges(self.mainwin)
  File "/usr/lib/python2.4/site-packages/pirut/__init__.py", line 557, in
applyChanges
    self.checkDeps(mainwin)
  File "/usr/lib/python2.4/site-packages/pirut/__init__.py", line 322, in checkDeps
    self.populateTs(keepold=0)
  File "/usr/lib/python2.4/site-packages/yum/depsolve.py", line 153, in populateTs
    self.downloadHeader(txmbr.po)
  File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 767, in
downloadHeader
    raise Errors.RepoError, saved_repo_error
RepoError: failed to retrieve getPackage/gnupg-1.4.5-13.i386.rpm from
rhel-i386-client-5
error was [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>

Local variables in innermost frame:
errors: {}
e: [Errno 2] No such file or directory:
'//var/cache/yum/rhel-i386-client-5/headers/gnupg-1.4.5-13.i386.hdr'
self: <__main__.PackageUpdater object at 0x95cccec>
saved_repo_error: failed to retrieve getPackage/gnupg-1.4.5-13.i386.rpm from
rhel-i386-client-5
error was [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
repo: rhel-i386-client-5
checkfunc: (<bound method PackageUpdater.verifyHeader of
<__main__.PackageUpdater object at 0x95cccec>>,
(<yum.sqlitesack.YumAvailablePackageSqlite instance at 0xa1ffcec>, 1), {})
local: //var/cache/yum/rhel-i386-client-5/headers/gnupg-1.4.5-13.i386.hdr
po: gnupg - 1.4.5-13.i386

The 2nd times I tried, it complained of unresolved dependencies.

Expected results:
   The software should download all the dependencies and continue with the
process rather than stopping.

Additional info: