Hello Chad,
The old Pila charger terminates the charge when the high voltage protection in the battery kicks in. If you put an unprotected battery in an old Pila charger, it will overcharge. When you overcharge Li-Ion chemistry you run the risk of an explosive fireball that is refereed to as rapidly venting accompanied by flame.
The new Pila IBC charger uses a normal Li-Ion charging algorithm and ends the charge at 4.2 volts. Pila "officially" does not recommend charging anything but Pila cells in their charger, but I have not been able to find any problems using it with other cells both protected and unprotected.
Tom