TIBStringField = class(TWideStringField)

constructor TStringField.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  SetDataType(ftString);
end;

constructor TWideStringField.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  SetDataType(ftWideString);
end;

procedure TdxCustomMemData.LoadFromDataSet(DataSet : TDataSet);

  function CanAssignTo(ASource, ADestination: TFieldType): Boolean;
  begin
    Result := ASource = ADestination;  // ftString <> ftWideString
    if not Result then
      Result := (ASource = ftAutoInc) and (ADestination = ftInteger);
  end;

var
  i : Integer;
  AField : TField;
  mField: TdxMemField;
begin
...
  while not DataSet.EOF do
  begin
    Append;
    for i := 0 to DataSet.FieldCount - 1 do
    begin
      AField := FindField(DataSet.Fields[i].FieldName);
      if(AField <> nil) and CanAssignTo(DataSet.Fields[i].DataType, AField.DataType) then
      begin