Multi plant, mrp and part version problem

Does anyone know of how to link a specific part version to a plant
so we do not have to do the problems below?

Does anyone else have a similar problem as described below and have
a work around for the above.

Background:

We have a client with a problem that we have several plants 100's
of KM from each other and they all have a different approved version
for each part.
They are one company
When they run MRP for plant A it is picking up the latest version
from the part master which is sometimes for plant B and the
following happens
Sometimes an unfirm job is created by MRP with the wrong version
Sometimes a suggestion instead by MRP because when it tried to
create an unfirm job the latest version had plant specific work
centers (you can see this in the MRP log).

Because they have a high volume of jobs being planned (they don't
keep stock as they are quick to make voluminous items).

They are having to either check the version on each unfirm jobs
before we release them or review the versions on a suggestion before
we firm them. This is quite a chore.

Your help appreciated - Thanks Team