SP2 Upgrade Issue

Had an issue while updating SQL Server 2005 RTM to SP2. The SISS packages would start and then go into a weird suspended mode.

The history error message was:
Step 1 of job 'Inventory Reconciliation Job' (0x2070EF085C1D99489E13145AC7D55282) cannot be run because the SSIS subsystem failed to load. The job has been suspended.

The answer was :

http://support.microsoft.com/?kbid=914171

The SQL that fixed it was:
use msdb
go

select * from msdb.dbo.syssubsystems;
/*
--useful bit commented out here
delete from msdb.dbo.syssubsystems
exec msdb.dbo.sp_verify_subsystems 1
*/
go