Comment 1 for bug 594581

Note that there are several alternative definitions for bipartite modularity, so we may have to be prepared for those as well. E.g.:

R. Guimerà, M. S.- Pardo, and L. A. N. Amaral, “Module identification in bipartite and directed networks,” Phys. Rev. E 76, 036102, 2007.
http://arxiv.org/abs/physics/0701151

And there's also this one:
http://portal.acm.org/citation.cfm?id=1557914.1557956