diff -Naur asterisk-addons-415.orig/chan_mobile.c asterisk-addons-415.patched-work/chan_mobile.c
--- asterisk-addons-415.orig/chan_mobile.c	2007-07-19 08:02:01.000000000 +0700
+++ asterisk-addons-415.patched-work/chan_mobile.c	2007-07-20 07:10:03.000000000 +0700
@@ -1788,7 +1788,9 @@
 		free(pvt);
 	}
 
-	sdp_close(sdp_session);
+	if (sdp_session) {
+		sdp_close(sdp_session);
+	}
 
 	return 0;