I guess this is result from the same problem mole sees. I have solved this by dropping the database and re-building it. I guess it would be enought to delete the latest block from the database, but have not had time to investigate this further. Auroracoin blockchain is still small enought..
Yes, unfortunately I think molecular is on the big chain. I started a module (Abe.admin) to delete problem data but didn't get to the "delete from block X onwards" function.