Yeah, the field your at NOW has 125%, but I'm betting the last time you flew that plane, it was from a field that had less. Since it saves your preferences the same as your last flight, you need to remember to set it back.
It's cool that it remembers how you had it set last time, but I agree, it would be great if it would "ignore" the setting when you are forced to take less fuel, but I don't really see how that could be easily done.