Iphone 3GS, update to 3.1 went smooth with no issues. Received a call prior and worked fine. Phone call afterward, no one can hear me. All other iphone/ipod sounds work as before. I can use Voice Commands and record a voice memo. I reset it several times, turned it on/off several times, restored to factory settings and restored latest backup, and even put in/removed the headset jack a couple dozed times. I can receive phone calls, send receive email & text messages. Everything appears to work except for the mic during a phone call. I give up, any ideas?