Ever since I've had my iPhone, when it reaches about 50% or less it just turns off without warning during use. The full charge does not last very long, after about 30 minutes of internet use if that, it goes down to about 75%. Then after reaching 50% the little wheel starts spinning and it turns off completely. Even after turning on, it doesn't stay on for long and turns off automatically. The only way to get it to stay on is to charge it for few minutes. HELP please. Oh year its unlocked and jail broken with the original attws sim card from before the cingular days. Any idas