If a tenant moves out part way through a rent period, then the amount owing in the last rent period is a percentage of the total amount normally due.  The NZ T41 Rent Summary report adheres to this, and so does the rent periods screen, however the Tenant History report was not.  It was always charging the full amount in the last rent period.  The Tenant History report has therefore been fixed so that the total balance at the end should always match the balance of the Rent Summary report.