Can't hear voice on incoming calls (iphone 2G and fw 3.0)

Hi there !

After upgrading and JB my iphone 2G , everything seems well but when i receive a call, i can't hear the voice of those who's speaking.

On the other side, they can hear my voice saying "hello ? helloooo ? hellooo ?" :D

Does anyone have had the same problem after upgrading ?
I think this afternoon i downgrade to 2.2.1

David

SOLVED myself :

just re-done an upgrade with an original FW 3.0 , then JBroked and Unlocked with redsn0w.

All right now, phone is working perfectly !