Issue with Superannuation Payment

We have been using the Superannuation Clearing House for many years to pay our super. I am now trying to set MYOB up to pay the super and I am almost there.

As far as I can tell everything is set up except now when I go to Pay Superannuation I get the following validation error: 

You need to enter a valid employee membership number for this employee.

I know the employee membership number is correct because it has been used correctly by the Superannuation Clearing house for many years and I have cut & paste from there.

Also, the employee has two lines in the list, one for the Superannuation Guarantee payment and one for Salary Sacrifice. The message is only occurring against the Salary Sacrifice line, the Superannuation Guarantee line has been accepted, and its the same superannuation fund.

What do I do?? I'm stuck.