I've created a bidirectional filtered multigraph from an adjacency_list with vectorS and listS as containers for the vertices and egdes respectively. It seems the function edge(u,v,g) does not work properly for this kind of graph. I can detect the existence of an edge (u,v) if I iterate explicitly through the out_edges of the filtered graph but not if I use edge() directly on the filtered graph. Also, I get an exception when I remove an edge that was invisible to the edge(u,v,g) function while the bidirectionnal version of remove_edge for adjacency_list is erasing the edge ID form the in_edge list of the graph. Any idea why edge() does not work in this case? Patrick --------------------------------- Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages!