diff --git a/addons/web/session.py b/addons/web/session.py
index 30e9308d4e1..8a083e0dec9 100644
--- a/addons/web/session.py
+++ b/addons/web/session.py
@@ -85,7 +85,7 @@ class OpenERPSession(object):
         self.jsonp_requests = {}     # FIXME use a LRU
 
     def send(self, service_name, method, *args):
-        code_string = "warning -- %s\n\n%s"
+        code_string = u"warning -- %s\n\n%s"
         try:
             return openerp.netsvc.dispatch_rpc(service_name, method, args)
         except openerp.osv.osv.except_osv, e:
@@ -95,13 +95,13 @@ class OpenERPSession(object):
         except openerp.exceptions.AccessError, e:
             raise xmlrpclib.Fault(code_string % ("AccessError", e), '')
         except openerp.exceptions.AccessDenied, e:
-            raise xmlrpclib.Fault('AccessDenied', str(e))
+            raise xmlrpclib.Fault('AccessDenied', openerp.tools.ustr(e))
         except openerp.exceptions.DeferredException, e:
             formatted_info = "".join(traceback.format_exception(*e.traceback))
-            raise xmlrpclib.Fault(openerp.tools.ustr(e.message), formatted_info)
+            raise xmlrpclib.Fault(openerp.tools.ustr(e), formatted_info)
         except Exception, e:
             formatted_info = "".join(traceback.format_exception(*(sys.exc_info())))
-            raise xmlrpclib.Fault(openerp.tools.exception_to_unicode(e), formatted_info)
+            raise xmlrpclib.Fault(openerp.tools.ustr(e), formatted_info)
 
     def proxy(self, service):
         return Service(self, service)