creating 2nd report is not working

[Cats&Dogs]

Tested on local 7.0 stable and on
runbot (Build 28684)
server (5214)
addons (9795)
web (4126)

Repreducing the wrong behavior:

- goto settings->Technical->Actions->Reports
- Search for invoice
- Open the basic invoice report (the one with a save as attachment prefix)
- Duplicate this entry, named it "invoice wo header"
- Edit the duplicated entry, disable "Add RML Header", Clear Save as Attachment prefix, disable reload from attachment
- Note the new id in the url, remember it for later use
- Goto settings->Technical->Actions->Action Bindings
- Search for Model name "Invoice"
- Duplicate the Invoices client_print_multi and rename it to invoice wo header, change the action reference with the previous noted ID.
- Goto Accounting->Customers->Customer Invoices
- Open an invoice, delete the attachment if present
- print the document using the print dropdown menu, eg Invoice
     OK : - document with header is created, and it is saved.
- print the document using the new menu invoice wo header
     Not OK : - document is still with header
- once again clear the attachment and start with printing using the newly created option
     Not OK : document is still with header, and attachment is created

This behavior is the same in all other reporting screens where you define a second, third, ... report based on the same or different RML file.