[Trunk] Problem with Split Payment on Supplier Invoice

OpenERP version 7 beta (nightly windows build as of 12/12/12
When creating a new invoice payment onto an invoice - It enters payments in the journal but not on the invoice.

To reproduce,
Add a new Invoice value eg 200
Click Pay
Enter a payment of say 100 against Cash
The payment shows correctly
Then try to add a payment of 100 also but this time against Bank
It does not show on the invoice - and the invoice shows an outstanding amount - but it adds an entry into payment to suppliers and to the journal.