Hello, I am trying to use this boost::graph implicit a-star search using boost 1.35.0 but have been having some difficulty. There seems to be a bug in the mutable_queue class where it will try to write to an index that is not valid: index_array[ tmp ] = c.size()-1; It seems someone else had posted an e-mail about this problem about four months ago. I checked CVS for any recent updates but this code hasn't been changed in the past 3 years. Anyways I got around this problem temporarily by adding some code to push indices onto the index_array until the code doesn't crash... not sure what the side effects of this would be though. Anyways after getting that working I find that my cost heuristic is never getting called! My implicit search basically goes off in the wrong direction to infinity. Anyways I've attached my test case. I've tried 2-3 different code samples that try to do this and none of them have worked so far! Chris