A teachers' union says the Government should commit more resources to fixing the troubled Novopay payroll system.
The latest report shows the error rate has fallen to acceptable levels, but there is still a backlog of problems to be fixed.
Since the system was introduced in August 2012, thousands of teachers and support staff have been wrongly paid.
Primary teachers union NZEI says while it's pleased the error rate has dropped, it had thought problems with the system would be resolved by the end of June.
It says some serious errors in the backlog have been there for nine months, and the Government needs to commit more resources.
Spokesperson Andrew Cassidy says a number of teachers have been overpaid paid tens of thousands of dollars, which means they have issues about taxation.
Mr Cassidy says some teachers' leave balances are also incorrect and have remained unresolved for months, causing them stress and anxiety.
The Minister responsible for Novopay, Steven Joyce, said on Tuesday he was happy with progress in fixing the system but acknowledged there is still work to be done recovering overpayments, fixing tax problems and correcting errors with leave balances.
He said clearing a backlog of over-payments is taking longer than expected and about 10,000 are outstanding, but has ruled out committing more resources at this stage.