Im having a prob with my phone...:( the battery gets low very fast and it suddenly drops down from full to 1bar while using... then when i keep it aside in my pocket it becomes full again...and some times it shows Not Charging error then i have to reinsert the charger and then it charges whats the problem the battery or the software? my phone is a year old..:(
I had a problem like it with the battery discharging to fast, you need to reset the batteries internal charge memory and it will work as normal again.
My problem is cause by daily charging of the battery when it is not fully discharged, i like a full battery each day and this daily charging make the battery forget its charge state.
To fix it you need to let it completely discharge untill the phone powers off and then leave it to recharge for at least 12 hours this resets the battery.