Microphone not working on speaker phone

I have the iPhone 4 and was doing face time and also calling a land line. When using face time or using the speaker phone on land line calls, the person on the other end is not able to hear me.

When using the phone in regular mode others have no problem hearing me (non-speaker phone).

Any ideas?

 

I want to add, when I use the memo recorder the mic works fine. Does this mean that it is a software issue?

 

Thanks all…. Last night I updated from 4.0 to 4.2 and that did nothing. I also reset to factory settings. Still not working.

I’m heading out of town tonight so I’ll try the restore in a couple of days.

 

Update:

I called Apple and did all of the reset options they run us through. Still did not solve the problem. Apple is sending me a new phone (closest store is 2K miles away)……..

 

They give you the option of sending them you phone and then they will send you a new phone. Which means you would be without a phone.

Or for $29 they will overnight you a new phone but they put a $700 hold on your credit card until they get the replaced phone back.

Or if you buy Apple care (which I did while on the phone call) they wave the $29 fee. Apple care was about $70.