up2date error

[dimensions]

we are using Plesk 8.0.1 with RHEL 4.

when we try to run up2date -l we get the following error:

An error has occurred:
exceptions.ValueError
See /var/log/up2date for more information

/var/log/up2date logs this:
[Thu Nov 9 20:31:21 2006] up2date updating login info
[Thu Nov 9 20:31:21 2006] up2date logging into up2date server
[Thu Nov 9 20:31:21 2006] up2date successfully retrieved authentication token from up2date server
[Thu Nov 9 20:31:21 2006] up2date availablePackageList from network
[Thu Nov 9 20:31:23 2006] up2date File "/usr/sbin/up2date", line 1288, in ?
sys.exit(main() or 0)
File "/usr/sbin/up2date", line 806, in main
fullUpdate, dryRun=options.dry_run))
File "/usr/sbin/up2date", line 1126, in batchRun
batch.init()
File "/usr/share/rhn/up2date_client/up2dateBatch.py", line 65, in init
self.__findPackagesToUpdate()
File "/usr/share/rhn/up2date_client/up2dateBatch.py", line 101, in __findPackagesToUpdate
plist.addGlobs(self.listOfGlobs)
File "/usr/share/rhn/up2date_client/packageList.py", line 161, in addGlobs
availList = rhnPackageInfo.getAvailablePackageList()
File "/usr/share/rhn/up2date_client/rhnPackageInfo.py", line 235, in getAvailablePackageList
package_list = availablePackageList(
File "/usr/share/rhn/up2date_client/rhnPackageInfo.py", line 169, in availablePackageList
progressCallback = progressCallback)
File "/usr/share/rhn/up2date_client/rpcServer.py", line 236, in doCall
ret = apply(method, args, kwargs)
File "/usr/share/rhn/up2date_client/repoDirector.py", line 22, in listPackages
return self.handlers[channel['type']].listPackages(channel, msgCallback, progressCallback)
File "/usr/share/rhn/up2date_client/rpmSource.py", line 229, in listPackages
msgCallback, progressCallback)
File "/usr/share/rhn/up2date_client/repoBackends/yumRepo.py", line 191, in listPackages
channelTimeStamp = time.strptime(oldVersion,"%Y%m%d%H%M%S")
File "/usr/lib/python2.3/_strptime.py", line 424, in strptime
raise ValueError("time data did not match format: data=%s fmt=%s" %

Strangely the same works on our other server with exactly the same configuration.

Any idea why this may be happening?