I too have this issue and like many others on here have seen many different work around's for it.
The question is though, why, why, why should we the consumer who spend our hard earned buck's on the iPhone put up with these problems?
Folks this is not by any means a cheap product it is in essence supposed to be the Ferrari of phones and ifyou had a problem with one of those, this kind of discussion would not be happening it would be fixed pronto.
The iPhone 4 had to have a cover to make it work and now we have the all singing all dancing iPhone 4s that lets face it has a plethora of problems and you have to disable most of it to get it to function.
All I can say is folks do not give up complaining. It's about time Apple sorted themselves out and stopped letting the consumer find fixes for their problems, who, lets face it, pays their wages. Oversights are one thing but when something effects your lifestyle that's another.
I have become seriously disillusioned by the iPhone so much so that almost certainly I will be looking elsewhere shortly.