I'm who posted #365817 recently in launchpad[0] about pagerank/arpack error.
In addition to that i was found some strange results. If you look the graph i'm attaching you'll see that vertex "3" should have more pagerank that "1" (isn't it?).
When i try pagerank using HEAD (also tried 0.5.2) (already tried with pagerank_old also) i'm getting: