Index: calendar/backends/groupwise/e-cal-backend-groupwise.c
===================================================================
--- calendar/backends/groupwise/e-cal-backend-groupwise.c	(revision 8329)
+++ calendar/backends/groupwise/e-cal-backend-groupwise.c	(working copy)
@@ -345,7 +345,8 @@
 
 	attempts = e_cal_backend_cache_get_key_value (cache, key);
 
-	g_static_mutex_lock (&connecting);
+	if (!g_static_mutex_trylock (&connecting))
+			return TRUE;
 
 	serv_time = e_cal_backend_cache_get_server_utc_time (cache);
 	if (serv_time) {
