This is indeed a sharepoint issue - I have a service request open with microsoft on this (SRZ080915000073). Analysis of the http traffic indicates that the problem is due to the fact that cookies are being correctly sent by the web part for the getMarkup operations, no cookies are being sent during the performBlockingInteraction requests, despite the fact that Set-Cookie headers are returned by the WSRP provider. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4208540#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...