Also getting mad to connect your vector points to the graph? Stuff like “node is unreachable”? Same thing here, till last week. In GRASS 6.3 (still CVS), the v.net tool was extended to easily connect nodes to a graph. Just specify the vector network map and the nodes map along with a distance threshold to only connect in a reasonable way.

Screenshot examples for GRASS vector networking can be seen here: travelling salesman analysis, Steiner Trees, and Iso-distances. Enjoy.