EXECUTE permission denied on sp_sqlagent_log_jobhistory when running a maintenance task or sql job

Question

Hi folks,
I have a scheduled maintenance plan and associated jobs in SQL Server 2008 SP2 that have been working but stopped about two months ago. When I run a maintenance task or sql job using any account (sa, sysadmin-priveleged domain account, etc) I get the following
entries in the SQL Server Agent log (see below). I've tried changing the SQL Server Agent account, applied the latest hotfixes (CU2 for 2008 SP2) and set permissions manually so that the service accounts have dbo access to the msdb database. Anyone got other
ideas? I've avoided recreating the msdb database, but that may be my only option.
Date  4/02/2011 3:42:40 PM
Log  SQL Server Agent (Current - 4/02/2011 3:23:00 PM)
Message
[298] SQLServer Error: 229, The EXECUTE permission was denied on the object 'sp_sqlagent_log_jobhistory', database 'msdb', schema 'dbo'. [SQLSTATE 42000] (ConnExecuteCachableOp)
Date  4/02/2011 3:42:40 PM
Log  SQL Server Agent (Current - 4/02/2011 3:23:00 PM)
Message
[298] SQLServer Error: 229, The EXECUTE permission was denied on the object 'agent_datetime', database 'msdb', schema 'dbo'. [SQLSTATE 42000] (ConnExecuteCachableOp)
Date  4/02/2011 3:42:40 PM
Log  SQL Server Agent (Current - 4/02/2011 3:23:00 PM)
Message
[298] SQLServer Error: 229, The EXECUTE permission was denied on the object 'sp_sqlagent_log_jobhistory', database 'msdb', schema 'dbo'. [SQLSTATE 42000] (ConnExecuteCachableOp)

Answer 1

And just to add to the confusion - I created a SQL login called sql-maintjobs and have it sysadmin priveleges. I then logged in to SQL using this account on the instance that is failing and ran the following:
declare
@backupjobid uniqueidentifier
select
@backupjobid=CONVERT(uniqueidentifier,
'2C4974D4-53BE-4E38-8EC0-8F5398CADE88')
exec
sp_sqlagent_log_jobhistory
@job_id = @backupjobid,
@step_id
=1,
@sql_message_id
= 0,
@sql_severity
= 0,
@message
=
NULL,
@run_status
=1,
-- SQLAGENT_EXEC_X code
@run_date
=19900101,
@run_time
=1,
@run_duration
=1,
@operator_id_emailed
= 0,
@operator_id_netsent
= 0,
@operator_id_paged
= 0,
@retries_attempted
=0,
@server
=
NULL,
@session_id
= 0
This sql worked fine - no permission errors at all. That would suggest the account does have permission to EXECUTE that stored procedure... very confusing!