Hours incorrect in payroll

I have recently amended an employee from Apprentice at 38 hrs a week to tradesman at 40 hours a week.  Since I made this change the employee in question has 40 hours automatically added to his timesheet.  So for instance, this week he worked 43 hours, so when I go to "pay employee" it has 83 hours.  This is the only employee it is doing it on and all I changed were his normal hours, his pay rate and classification.  

I have checked his pay basis is Hourly, the wage category is Base hourly, based on Hours not salary.  

Thank you