applied a modified version of Christof Musik's multihead patch (though this is not sure if it works in all cases, have to wait for an ACK by Christof)

event.c

@@ -270,8 +270,11 @@ static void
 leavenotify(XEvent *e) {
 	XCrossingEvent *ev = &e->xcrossing;
 
-	if((ev->window == root) && !ev->same_screen)
+	if((ev->window == root) && !ev->same_screen) {
 		issel = False;
+		if(sel)
+			XSetWindowBorder(dpy, sel->win, dc.norm[ColBorder]);
+	}
 }
 
 static void