I have a (non-jail broken) iphone 4 running 7.1.2 software and today noticed that unless the speaker phone is on, the person you are calling can't be heard (but they can hear me). I'm sure that I didn't change anything in settings (I hardly ever go in there), the phone wasn't dropped, etc. Anything other than a hardware problem come to mind? I'm not sure when the software was updated but could it be issues with 7.1.2?