When you create a new maintenance plan that runs on a schedule in Microsoft SQL Server 2005, you may receive the following error message:
Create maintenance plan failed.Additional information:Create failed for JobStep 'Subplan'. (Microsoft.SqlServer.MaintenancePlanTasks)
An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
The specified '@subsystem' is invalid (valid values are returned by sp_enum_sqlagent_subsystems). (Microsoft SQL Server, Error 14234)
This problem occur because you didn't install Integration Services service from the SQL Server 2005 CD, just add the component and the error will not appear again.