Contact/Opportunity relationship: Missing 'Role' field in the Opportunities 'Contact subpanel'

Hi,

Did somebody get a solution on displaying the contact role starting from the contact detail view and looking to the opportunity subpanel or something similar?
I tried what suggested by PStevens (turning opportunity role field studio to “true”, in varfed.php). I could see the opportunity role but once added the field to the edit or detail or contact list view I could select an option from the role menu, but once save it did not display anything I selected (always blank).

Thanks
Mario