I have been having issues with SCCM/WSUS updates failing to automatically synchronise updates on a schedule.
My WSYNCMGR.log shows :-
Sync failed: There is an error in XML document (129, 22981430). Source: Microsoft.UpdateServices.Internal.ApiRemoting.ExecuteSPSearchUpdates
... and it will retry every hour, failing with the same error.
If I do a manually initiated "Syncronise" from the SCCM console all appears to run through OK until the next scheduled automatic sync when the error starts again.
Not alot seems to be documented ont he web about this - Any ideas anyone?