Multiple location in Single Invoice - 2007 B

Dear All,

It is known that the location is mandatory that too same in a single marketing document for 2007 version. the problem is, we have recently upgraded a 2005 database with open delivery documents to 2007. the warehouses in all those documents are having different locations. after upgrading to 2007 version, even after giving the same location value in all these warehouses, the invoice that we are creating in 2007 have those original location. the only way to change it or refresh it is, delete the warehouse value in invoice and again select it from CFL. but once the delivery is prepared, warehouse cant be edited in Invoice. so we are kind of stuck. we are not able to create the invoice document as the locations are not refreshed. SAP picks up the location from base document. what should we do?

Thanks,

Binita