Always invalidate media on shutdown to avoid remnants.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3533 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/AbstractMedia.java

@@ -1,5 +1,5 @@
 //
-// $Id: AbstractMedia.java,v 1.13 2004/11/11 23:52:43 mdb Exp $
+// $Id$
 //
 // Narya library - tools for developing networked games
 // Copyright (C) 2002-2004 Three Rings Design, Inc., All Rights Reserved
@@ -275,6 +275,7 @@ public abstract class AbstractMedia
      */
     protected void shutdown ()
     {
+        invalidate();
         _mgr = null;
     }