I had my 3GS jailbroken under version 4.0.1 and figured that may be the reason. I updated my iPhone to 4.2 software and the controltalk still isnt working. It works on my friends iPhone, leading me to believe there's something wrong with mine. I tried cleaning out my audio jack with a qtip dipped in rubbing alcohol (it did bring out some lent) but that didn't help either. Anyone with any suggestions with what my next move should be or what could be wrong?