--- a/jingle/action-handlers.c	Tue Aug 10 23:54:37 2010 +0200
+++ b/jingle/action-handlers.c	Wed Aug 11 00:10:09 2010 +0200
@@ -348,7 +348,7 @@
   // We're looking if the session exist
   sess = session_find_by_sid(jn->sid, from);
   if (sess == NULL) {
-    // TODO: send unknow-session
+    jingle_send_iq_error(jn->message, "cancel", "item-not-found", "unknown-session");
     return;
   }