Index: network-manager-0.8.1/src/nm-device-wifi.c
===================================================================
--- network-manager-0.8.1.orig/src/nm-device-wifi.c	2011-01-02 14:56:46.256018587 -0200
+++ network-manager-0.8.1/src/nm-device-wifi.c	2011-01-02 14:56:59.076518077 -0200
@@ -1828,6 +1828,9 @@
 	GValue instance = { 0, };
 	GValue retval = { 0, };
 
+	if (nm_device_get_state (NM_DEVICE (self)) == NM_DEVICE_STATE_ACTIVATED)
+		return FALSE;
+
 	g_value_init (&instance, G_TYPE_OBJECT);
 	g_value_take_object (&instance, self);