Bank Reconciliation issue

So I am trying to catch up from what our previos accountant failed to do, and complete the bank reconciliations for the last year. So I have unallocated all of the transactions so it as if they have not occurred yet. I then allocate the month that I am completing the reconciliation for and complete the reconciliation. I have successfully done 3 months this way, however I have now hit a snag. I CANNOT get october to reconcile, all of the transactions are correct. I have double checked that the balance on the bank statement is correct. I have no idea where else to look!! Please help!!