The whole system changes on 1 May (3 bands only etc). However, the problem was that JPA was not programmed to recognise or deal with certain groups who kept grandfather rights to a higher rate of LOA than that applicable to their rank. This underpayment will have occured between JPA launch (Mar 06 to present date) I understand that it took some years for the BZN individual to finally wrench the money out of the sytem, but I would suggest that anyone in similar circumstances contacts their handbrake house and make them aware of the case. The PACC who actioned the case will be certainly aware! PM me if you want the details that would otherwise bore other readers.
Rgds
Vasco