--- if_bwn.c	2009-12-22 16:32:53.000000000 -0800
+++ /mnt/t62/sys/dev/bwn/if_bwn.c	2010-01-01 14:45:43.000000000 -0800
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2008 Weongyo Jeong <weongyo@freebsd.org>
+ * Copyright (c) 2009-2010 Weongyo Jeong <weongyo@freebsd.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -792,6 +792,8 @@
 	struct ieee80211com *ic = ifp->if_l2com;
 	int i;
 
+	sc->sc_flags |= BWN_FLAG_INVALID;
+
 	if (device_is_attached(sc->sc_dev)) {
 		bwn_stop(sc, 1);
 		callout_drain(&sc->sc_task_ch);
@@ -2760,14 +2762,14 @@
 
 	if (mac->mac_status >= BWN_MAC_STATUS_INITED) {
 		/* XXX FIXME opmode not based on VAP */
-		memset(sc->sc_macaddr, 0, IEEE80211_ADDR_LEN);
 		bwn_set_opmode(mac);
 		bwn_set_macaddr(mac);
 	}
 
 	if (mac->mac_status >= BWN_MAC_STATUS_STARTED)
 		bwn_core_stop(mac);
-	bwn_core_exit(mac);
+	if (sc->sc_flags & BWN_FLAG_INVALID)
+		bwn_core_exit(mac);
 	sc->sc_rf_enabled = 0;
 
 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);