Novell ZENworks 10 Configuration Management with Support Pack 1 - 10.1 Patch Management
Microsoft Windows XP Professional Windows XP Professional Support Pack 2
The Discover Applicable Updates bundles do not get assigned to windows XP devices.
This is fixed in version 10.1.1 - see KB 7001406 "ZENworks 10 Configuration Management 10.1.1 - patch information and list of fixes" which can be found at https://www.novell.com/support
This was an issue with the language coming back from the device being null.