I've has my iPhone 4 for a few months now and have been running in to some issues with audio playback. It started a few months back, I was sat in the garden listening to some podcasts through the headphones when the audio started to crackle, within the space of a minute it got gradually worse until all I could hear was static, I changed the headphones and tried to see if the internal speakers were any different but they were the same. It was quite a hot day and the phone is kept in a black rubber cover but sat in almost direct sunlight, I didn't get any temperature warnings though. I turned the phone off for a whole and went back in doors. When I turned it back on it was working fine and I had no further issues for the rest of the day. A few weeks later I was listening to some songs in my car using an fm tuner attacent and the audio started breaking up exactly as before, I unplugged the tuner and the internal speakers were making the same cracklig sound, again its hot in the car - around 25C but the phone was not on direct sunlight. Iturned the phone off for about 30 seconds and turned it back on and it started working again, this time not for too long though and it started breaking up again. I turned it off and when I got home it was workin fine. Every now and then though the audio stops working, some times it is preceded by the crackling sound, sometimes not. Any ideas what is goingg wrong with it?