Problems inherent with defining a center of circulation in tropical systems are well-documented in the case of Hanna here. As several users have noted, the COC has seemingly been farther north than the official fixes. This all has a bearing on the short term forecast accuracy. I do agree, though, that Hanna will hang around the central/SE Bahamas until Thursday (waiting for Gustav to do it's thing first?). Look for Hanna to get stronger and more organized by then as well.