Not yet prominently covered by the finance media in the US: boardroom troubles at Petrobras, the company that was once the national oil company of Brazil, that was privatized in 2010 but that remains of great importance there (and in the South American continent in general) -- this looks like something that could explode into big front page headlines soon. (Its impressive looking HQ building in Rio is portrayed here.) The chairman of the board has taken a temporary leave of absence, after only five months on the job. The company isn't saying why, except for a terse reference to "personal reasons." Does this mean he is retiring, and simply hopes to play a lot of golf? Almost certainly not. After all, Murilo Ferreira remains a member of the board of Vale SA< Brazil's big mining corp., a task which one presumes also cuts into golf time. So what is there specific about Petrobras that requires he be absent? Petrobras contends these days with a bid rigging and br...