Internal Requisitions not getting approved

I have done a complete setup for 2 INV orgs under one OU. I can create POs/Reqs for these 2 Orgs & receive it too.

I have also done the necessary setups for ISO. (Metalink Note 1384716.1)

After creating a IR when i press Approve, the IR is not getting approved. It remains in Incomplete Status.

I have not changed the Approval groups/limits or assignments.

What can be the issue here ?

Inter-Org transfer is not the option as it will mes with planning/demand/supply at both places.

Thanks in advance.