Hi
Ever since upgrading my 3GS to 4.0.2, callers to the car experience hearing themselves, all the time. Doesn't matter whether they are using a land line or mobile, same issue.
My own voice sounds fine to the caller as does their voice to me - its just their voice to themselves that echoes constantly.
May have to roll back to an earlier version of Apple OS but not sure how to do this.

Any help gladly received.
Thanks