Need Help on Log Error Message During Windows Update

On a Windows 2003 server, when pressing the Custom button on the Windows
Update page, the Network Service is writing the following line repeatedly
into the logfile at:

C:\WINDOWS\system32\wbem\Logs\Framework.log

Text of the error is:

Shell Name Explorer.exe in Registry not found in process list. 01/04/2007
23:51:44.391 thread:3776
[d:\srvrtm\admin\wmi\wbem\providers\win32provider\c ommon\implogonuser.cpp.16
3]
Unable to locate Shell Process, Impersonation failed. 01/04/2007
23:51:44.391 thread:3776
[d:\srvrtm\admin\wmi\wbem\providers\win32provider\c ommon\implogonuser.cpp.17
5]

The Network Services DOES have the "Impersonate client after authentication"
User Right in Group Policy, so it's not failing for that reason.

What does the above error mean and how do I correct the situation?

--
Will