xxforms:get-request-header('orbeon-liferay-user-roles') returns only first role Orbeon 4 rc1 PE

I tried this function

xxforms:get-request-header('orbeon-liferay-user-roles')

in a form I created. As stated in a previous post, in Orbeon Proxy Portlet it does not return anything while in the Form Runner portlet it works but it returns only the first role and not the list of roles as stated in http://wiki.orbeon.com/forms/doc/developer-guide/admin/deployment-portlet.

Can anyone help?