diff --git a/larpe/trunk/larpe/saml2.ptl b/larpe/trunk/larpe/saml2.ptl
index 0357c7c..b0aefc2 100644
--- a/larpe/trunk/larpe/saml2.ptl
+++ b/larpe/trunk/larpe/saml2.ptl
@@ -77,6 +77,7 @@ class Saml2(Saml2Directory):
         return self.sso_after_response(login)
 
     def sso_after_response(self, login):
+        providerId = login.server.providerId
         try:
             assertion = login.response.assertion[0]
             if assertion.subject.subjectConfirmation.subjectConfirmationData.recipient != \
@@ -103,7 +104,7 @@ class Saml2(Saml2Directory):
         try:
             audience_ok = False
             for audience_restriction in assertion.conditions.audienceRestriction:
-                if audience_restriction.audience != login.server.providerId:
+                if audience_restriction.audience != providerId:
                     return template.error_page('Incorrect AudienceRestriction')
                 audience_ok = True
             if not audience_ok:
@@ -129,12 +130,14 @@ class Saml2(Saml2Directory):
         session = get_session()
         if login.isSessionDirty:
             if login.session:
-                session.lasso_session_dumps[login.server.providerId] = login.session.dump()
+                session.lasso_session_dumps[providerId] = login.session.dump()
+                session.lasso_session_indexes[providerId] = assertion.authnStatement[0].sessionIndex
+                session.lasso_session_name_identifiers[providerId] = login.nameIdentifier.content
             else:
                 session.lasso_session_dumps[login.server.providerId] = None
 
         if assertion.authnStatement[0].sessionIndex:
-            session.lasso_session_index = assertion.authnStatement[0].sessionIndex
+            session.lasso_session_indexes = assertion.authnStatement[0].sessionIndex
 
         user = self.lookup_user(session, login)
 
@@ -301,11 +304,17 @@ class Saml2(Saml2Directory):
             return
 
         logout = lasso.Logout(misc.get_lasso_server(protocol = 'saml2'))
+        providerId = logout.server.providerId
         logout.processRequestMsg(soap_message)
         name_identifier = logout.nameIdentifier.content
+        # find one session matching the name identifier, and eventually the request
         for session in get_session_manager().values():
-            user = session.get_user(logout.server.providerId)
-            if user and logout.nameIdentifier.content in user.name_identifiers:
+            session_index = session.lasso_session_indexes.get(providerId)
+            name_identifier = session.lasso_session_name_identifiers.get(providerId)
+            request_name_identifier = logout.nameIdentifier.content
+            request_session_index = logout.request.sessionIndex
+            if request_name_identifier == name_identifier and \
+                    (not session_index or request_session_index == session_index):
                 get_logger().info('SLO/SOAP from %s' % logout.remoteProviderId)
                 break
         else:
@@ -375,10 +384,15 @@ class Saml2(Saml2Directory):
             get_session_manager().expire_session(logout.server.providerId)
 
         try:
-            if not logout.request.sessionIndex:
-                for session2 in get_session_manager().values():
-                    if name_identifier == session2.name_identifier:
-                        del get_session_manager()[session2.id]
+            providerId = logout.server.providerId
+            session_index = logout.request.sessionIndex
+            name_identifier = logout.nameIdentifier.content
+            # Remove all session for this name_identifier and if present for this session index
+            for session2 in get_session_manager().values():
+                if session2.lasso_session_name_identifiers.get(providerId) == name_identifier \
+                        and ( not session_index
+                                or session2.lasso_session_indexes.get(providerId) == session_index):
+                    del get_session_manager()[session2.id]
         except:
             # killing all session failed, ignoring silently
             pass
diff --git a/larpe/trunk/larpe/sessions.py b/larpe/trunk/larpe/sessions.py
index 7c3c6b1..465df16 100644
--- a/larpe/trunk/larpe/sessions.py
+++ b/larpe/trunk/larpe/sessions.py
@@ -16,9 +16,17 @@ class BasicSession(Session):
     def __init__(self, id):
         self.users = {}
         self.lasso_session_dumps = {}
+        self.lasso_session_indexes = {}
+        self.lasso_session_name_identifiers = {}
         self.provider_id = None
         Session.__init__(self, id)
 
+    # lasso_session_indexes newly introduced
+    def __setstate__(self, dict):
+        self.lasso_session_indexes = {}
+        self.lasso_session_name_identifiers = {}
+        self.__dict__.update(dict)
+
     def has_info(self):
         return self.users or self.lasso_session_dumps or self.provider_id or Session.has_info(self)
     is_dirty = has_info