Account number for transaction type Inventory inter-unit receivable does not exist

Hi All

I am having problems posting transfer order between two sites

Inventory management > Outbound orders > Transfer order

When I ok ship transfer order, I get the following error message 

"Account number for transaction type Inventory inter-unit receivable does not exist"

I then found I needed to setup Inventory inter-unit receivable and Inventory inter-unit payable

General ledger > Posting setup > Accounts for automatic transactions 

However when going back and posting I am still getting the same error.

Hope someone can help.

Thanks