You should try to indentify if the problem is at your end or at the other end of the call.
Do you have the same problem with only that one contact, or more than one.
Does that contact have the same problem only with you, or with others as well.
Try a call to the Echo test contact. See if you hear your own voice played back to you there.
Please note: I do not respond to requests for help via Private Message.
