Same aweful problem.
It seems that second microphone is problematic.
During a call every thing is ok until I click the speaker. I can hear the peer clearly but he/she can not hear me clearly and I should shout.
Same problem when recording a sound using any recorder or taking films with the camera.
So using skype or same programs is impossible for me.
The retailer says that it is a software problem but I think it is faulty.
I made soft reset bot nothing chages.
I am living in iran and there is no guaranty for nokia mobiles inside iran and I feel sad these days.