Custom Error Messages in Sourcing Cockpit do not prevent PO creation

Hi forum gurus,

We are implementing SRM 5.5 SP 9 in extended classic mode. We have implemented sourcing cockpit too.

We have coded an error message in the 'BBP_ITEM_CHECK' BADI for the sourcing cockpit and it appears correctly in the sourcing cockpit when necessary.

However, the system still allows the PO to be created, despite the error message being visible prior to clicking on the 'Create Purchase Order' button.

Any ideas? I will create a customer message to SAP with this anyway, but hoped someone may know for certain how to resolve it!

Thanks,

Nick