Different rate for same person based on organization doesn't work

Hi,

we want to define different cost rate to the same named person based on the organization of the task on which the resource is planned.

We have tried to define two rate schedule for the same named person and two organization costing rule (for two different organization) each one linked to the right rate schedule previoulsy create.

We have tried with an RBS that contain only "named person" and with another RBS that contain "Organization:NamedPerson" but the result it's the same. It doesn't work. ("A raw cost rate wasn't found for the planning transaction")

Do you know why ?