I should add that my portlet uses the "standard"
PortletSession session = request.getPortletSession();
to handle sessions. I've been reading a lot about JBoss WSRP using cookies to handle sessions. Maybe I need to code differently?
There is indeed an issue with BEA as a consumer. A JIRA issue has been created for that and a solution has been found (thanks to the collaboration of fattymelt, trying my fixes live on his setup) :