Only A System Administrator Can Reassign Ownership

Hi guys,

I am new to this forum and new to SQL.

I have a stored procedure which sets the value of a variable (@owner_logon_name, type sysname) to sa. It then calls sp_add_job in the msdb database, which in turn calls numerous other stored procedures. The ASP page I post down to the server is coming back with an internal server error and the log file shows the following message:

"Only a system administrator can reassign ownership of a job."

Even though the login name was set to sa, it seems to be using another role.

The code I have in my sp is:

exec @ReturnCode = msdb.dbo.sp_add_job @job_id = @JobID output ,
@job_name = @JobName,
@owner_login_name = sa,
@description etc, etc

Can anyone think why it would do this? An explanation of how sp_add_job works would also be much apprciated.