Default Headphone plugged in, Mic Doesnt Work ?

Guys,

I recently updated my OPO to 30O. Now I cannot make use headphones to make calls or recive calls, as I can hear them speaking but they cant hear me. I have tried to record voice using sound record.

Have tried couple of headphones, same result. It this something related to Stock ? I didnt try any other ROM.

I am on stock, and no Mods. Any suggestions ?

Thanks

Zaib