CGAL users discussion list

Hello,
I have a problem using segment_delaunay_graph_2.h.
when I want to compile my project, in the above file I get several errors:

for "typedef typename Geom_traits::Arrangement_type_2  AT2;":
error C2039: 'Arrangement_type_2' : is not a member of 'CGAL::Sdgtw2<Gt_base>'
        with
        [
            Gt_base=int
        ]

for these lines:
  typedef typename Storage_traits::Point_container     Point_container;
  typedef typename Storage_traits::Point_handle        Point_handle;
  typedef typename Storage_traits::const_Point_handle  const_Point_handle;
I get:
error C2039: 'const_Point_handle' & 'Point_handle' & 'Point_container': is 
not a member of 'CGAL::Boolean_tag<b>'
        with
        [
            b=true
        ]

and for site_2 and others...

but when I run the demo of segment delaunay, there is no problem. I did not 
explicitly set tag to true, but I wonder how this was done.

In reference manual (page 2001), these are defined for "DelaunayGraph 2":
>Types
>typedef Gt Geom traits; A type for the geometric traits.
>typedef DS Data structure; A type for the underlying data structure.
>typedef Data structure Triangulation data structure;
>This type has been added so that the
>Segment Delaunay graph 2<Gt,DS> class
>is a model of the DelaunayGraph 2 concept.
>typedef typename DS::size type size type; Size type (an unsigned integral 
>>type)
>typedef typename Gt::Point 2 Point 2; A type for the point defined in the 
>>geometric
>traits.
>typedef typename Gt::Site 2 Site 2; A type for the segment Delaunay graph
>site, defined in the geometric traits.
>Segment Delaunay graph 2<Gt,DS>:: Point container A type for the container 
>of >points.
>typedef typename Point container::iterator Point handle; A handle for points 
>>in the point container.

so who is causing this problem? it is now the third day I am struggling with 
this error?