diff -up openbox-3.4.7.2/openbox/session.c.autostartid openbox-3.4.7.2/openbox/session.c
--- openbox-3.4.7.2/openbox/session.c.autostartid	2008-04-14 01:22:12.000000000 +0200
+++ openbox-3.4.7.2/openbox/session.c	2008-12-09 18:04:50.000000000 +0100
@@ -174,6 +174,16 @@ static gboolean session_connect(void)
 
     /* connect to the server */
     oldid = ob_sm_id;
+
+    if (!oldid) {
+        const gchar *autostart_id = g_getenv("DESKTOP_AUTOSTART_ID");
+
+        if (autostart_id) {
+            oldid = g_strdup(autostart_id);
+            g_unsetenv("DESKTOP_AUTOSTART_ID");
+        }
+    }
+
     ob_debug_type(OB_DEBUG_SM, "Connecting to SM with id: %s\n",
                   oldid ? oldid : "(null)");
     sm_conn = SmcOpenConnection(NULL, NULL, 1, 0,