J1.7.1/VM2 SVN revision 4355
This error message was introduced with revision 4348 (work on the title tag for categories view?). A menu item linked to the categories view produces:
Fatal error: Class 'JParameter' not found in ...\components\com_virtuemart\views\categories\view.html.php on line 74
Line 74: $menu_params = new JParameter( $menu->params );
fixed