Added using namespace osgDB to try and resolve some of the VS6.0 problems.

src/osgPlugins/osga/OSGA_Archive.h

@@ -1,7 +1,22 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2004 Robert Osfield 
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * OpenSceneGraph Public License for more details.
+*/
+
 #include <osg/Notify>
 #include <osgDB/Archive>
 #include <osgDB/FileNameUtils>
 
+using namespace osgDB;
+
 class OSGA_Archive : public osgDB::Archive
 {
     public: