Hi, Sorry to find another bug when I know you're busy. :( I guess this was broken when the graph property attributes were renamed/refactored: import boost.graph as bgl import pickle g = bgl.Graph() p = g.add_vertex_property( 'prop', 'float' ) pickle.dump( g, open( 'graph.pickle', 'w' ) ) pickle.load( open( 'graph.pickle', 'r' ) ) raises the following error: 1368 1369 def load(file): -> 1370 return Unpickler(file).load() 1371 1372 def loads(str): c:\apps\Python25\lib\pickle.py in load(self) 856 while 1: 857 key = read(1) --> 858 dispatch[key](self) 859 except _Stop, stopinst: 860 return stopinst.value c:\apps\Python25\lib\pickle.py in load_build(self) 1215 setstate = getattr(inst, "__setstate__", None) 1216 if setstate: -> 1217 setstate(state) 1218 return 1219 slotstate = None : 'Graph' object has no attribute 'vertex_property_map' John.