Boost Subgraph Copy Constructor not working with Qt 5.0.2 and MinGW

[mayur_narkhede]

I was using Qt 4.8 and minGW compiler with boost 1.46.0 for my project but now i have moved to Qt 5.0.2 and MinGW compiler with Boost 1.55.0, But the copy constructor for subgraph is not working well. It is not adding vertices to subgraph (Shows 0 items in vertex list if performed debug).

@typedef boost::adjacency_list< boost::listS,
boost::vecS,
boost::bidirectionalS,
boost::property<boost::vertex_index_t, int ,
property<vertex_position_t, point, VertexProperties> > ,
boost::property<boost::edge_index_t,int , EdgeProperties>,
boost::property<graph_custom_prop_t,GraphProperties> >
Graph;
typedef boost::subgraph< Graph > SubGraph;@

I am taking input into gMainGraph and I need to copy it to m_gMainGraph

@SubGraph* m_gMainGraph;
m_gMainGraph = new SubGraph(gMainGraph);@

Subgraphs are getting created but the vertices and edges within subgraphs are not getting created and are getting added only to the top most parent graph. Here in above code gMainGraph is not getting deep copied to m_gMainGraph.
Any help would be appreciated,
Thank You