--- b/sys/dev/atkbdc/psm.c	
+++ b/sys/dev/atkbdc/psm.c	
@@ -3658,12 +3658,13 @@ proc_synaptics_mux(struct psm_softc *sc, packetbuf_t *pb)
 			pb->ipacket[0] &= 0xfb;
 			pb->ipacket[3] &= 0xfb;
 		}
-		sc->muxsave[0] = 0;
+		sc->muxsave[0] &= 0x30;
 		break;
 
 	default:	/* Generic mouse (Trackpoint) packet */
 		/* Filter out middle button events induced by some w values */
-		if (sc->muxmsbuttons & 0x03 || pb->ipacket[0] & 0x03)
+		if (sc->muxmsbuttons & 0x03 || pb->ipacket[0] & 0x03 ||
+		    sc->muxsave[0] & 0x30 || sc->muxsave[2] != 0)
 			pb->ipacket[0] &= 0xfb;
 		sc->muxmsbuttons = pb->ipacket[0] & 0x07;
 		/* Convert to Synaptics pass-through protocol */