Original post by: johnplim ,
I know this is an old thread, but, just in case somebody is having this problem today and is searching for any answers, my 3GS had this problem but no more. Basically I narrowed it down to the electrical outlet being used. I didn't believe it at first but after trying different outlets in my house the same thing happened. So try different outlets. I suspect some outlets have more electrical noise than others thus confusing the IPhone. Even try an outlet at somebody elses house.