Lipo battery out of Balance question

[KartRacer]

I have two 5000MAH 6 cell lipo's about a year old. Kept in controlled temp environment and storage charged regularly. One of the batteries has a cell that drops quicker than the rest. All except this one are within a .01 volt. The sixth cell drops .12 volts. When the battery is balance charged the charger gets it in balance. Should I be concerned about using the battery? Should I do something to remedy the situation? Or just quit worrying about it

[KartRacer]

Could really use some experienced input . I am concerned about using these cells.
Thanks in advance for your input.