Hi Juliana,
Check whether you have created the pay scale area and pay scale type in tables V_T510G/V_T510A and also do check whether you have assigned the pay scale type and area to the enterprise structure in table V_001P_C.
Also you can default the pay scale type and area in 0008 through the TARIF feature. Though you have maintained the table T710 i hope you must have missed out the entry in V_001P_C.
Regards,
Mithun K