diff --git a/src_main/core/piobject.cpp b/src_main/core/piobject.cpp
index 45f386b5..1f1451d0 100755
--- a/src_main/core/piobject.cpp
+++ b/src_main/core/piobject.cpp
@@ -360,9 +360,13 @@ void PIObject::piDisconnect(PIObject * src) {
 	PIMutexLocker _ml(src->mutex_connect);
 	PIVector<PIObject * > cv = src->connectors.toVector();
 	piForeach (PIObject * o, cv) {
-		if (o == src) continue;
+		//piCout << "disconnect"<< src->className()<< o->className();
+		if (!o || (o == src)) continue;
+		if (!o->isPIObject()) continue;
 #ifndef ANDROID
+#  ifndef MAC_OS
 		PIMutexLocker _mld(o->mutex_connect, src != o);
+#  endif
 #endif
 		PIVector<__Connection> & oc(o->connections);
 		for (int i = 0; i < oc.size_s(); ++i) {
@@ -373,8 +377,10 @@ void PIObject::piDisconnect(PIObject * src) {
 			}
 		}
 	}
-	piForeachC (PIObject::__Connection & c, src->connections)
+	piForeachC (PIObject::__Connection & c, src->connections) {
+		if (!c.dest_o->isPIObject()) continue;
 		c.dest_o->connectors.remove(src);
+	}
 	src->connections.clear();
 }