lipo voltage diff between cell

I,ve a FlightPower 3s pack that cell number 2 is lower than the other, but this is arrive just this week. I have charge my pack monday, all the cells was equal. Tuesday i,ve play with my truck and dump the pack thru the LVC set at 9.6 volts. Reinstall the pack on the charger and .......the cell number two have a 0.075 volts of difference with cell number one and cell number 3.

What can cause this and is the difference is too much???

What can i do to resolve this??

Thank you