Index: madwifi-trunk-r3314/ath/if_ath.c
===================================================================
--- madwifi-trunk-r3314.orig/ath/if_ath.c	2008-02-20 18:10:48.315267722 +0100
+++ madwifi-trunk-r3314/ath/if_ath.c	2008-02-20 18:10:48.567282084 +0100
@@ -6474,8 +6474,9 @@
 			/*
 			 * Reject error frames if we have no vaps that
 			 * are operating in monitor mode.
+			 * Reject empty frames as well
 			 */
-			if (sc->sc_nmonvaps == 0)
+			if ((sc->sc_nmonvaps == 0) || (rs->rs_datalen == 0))
 				goto rx_next;
 		}
 rx_accept: