ODS to Cube Update

Hi Friends:

I am trying to load data into the Cube from the ODS. Env is TEST. The Test Box is closed from Modifications. Data is loaded into the ODS and activated. When i try to Update Data in Data Target and choose Initial Update and try to start immediately i get the following error:

SAP System has status 'not modifiable'.

I checked the Infopackage setting under RSA1->Transport connection->OBject Changeability and it is Change Original.

could someone throw some more light here.

Thanks

Mathew John