What in the apex class code is causing the 6 month schedule to calculate at 10% VS 8% commission amount? 
This is the first time this happened. Previous to this, the apex class code worked perfectly on this calculation previously. 

Above is the coding. We pushed it to production 1/13/16. In theory all Opportunities generated after that date should popluate these reults on the commissions field given the conditions listed in the class. But some are not- see below report.