Occasionally the Superannuation is calculated incorrectly, it happens to different employees.
The reason this is happening is because there is some corruption in the data file. You will need to do a triple rebuild of Super.
You need to do three rebuilds:
1) On the first rebuild select Rebuild Super.
2) On the second rebuild select Recalculate YTD Figures.
3) On the third rebuild select Rebuild Record Positions And Keys, Fix Invalid Employee Records, Fix Invalid Pay Records and Fix Or Remove Invalid Other Records.
Before each rebuild a backup will have to be made, make sure you use different disks for each backup and don't overwrite any existing backups.