Any idea ?

I use MySQL 3.23.49 running on my laptop running Windows-Me 4.90.3000. I'm
connected using MySQL ODBC driver 2.50.39.00 with Delphi 7 ADO components
and MDAC 2.70.9001.0 which comes with Delphi 7 build 4.453.

Code used to insert a row in the table:
procedure TForm2.AddRowButtonClick(Sender: TObject);
var
     LinesStream : TStream;
begin
     ADOQuery1.Close;
     ADOQuery1.SQL.Clear;
     ADOQuery1.SQL.Add('INSERT INTO Documents(DocId, DocDate, DocClass,
DocLines) ' +
                       'VALUES(:DocId, :DocDate, :DocClass, :DocLines)');
     ADOQuery1.Parameters.ParamByName('DocId').Value   := 'ABCD';
     ADOQuery1.Parameters.ParamByName('DocDate').Value := '22/09/2002';
     ADOQuery1.Parameters.ParamByName('DocClass').Value := 'Test';
     LinesStream := TMemoryStream.Create;
     LinesStream.Write('Hello World', 11);
     LinesStream.Seek(0,0);

ADOQuery1.Parameters.ParamByName('DocLines').LoadFromStream(LinesStream,
ftBlob);  // INVALID TYPE ERROR HERE
     LinesStream.Destroy;
     ADOQuery1.ExecSQL;
     ADOQuery1.Close;
end;

Code used to create the table:
procedure TForm2.CreateTableButtonClick(Sender: TObject);
begin
     ADOQuery1.Close;
     ADOQuery1.SQL.Add(
         'CREATE TABLE Documents (' +
           'DocId VARCHAR(8) PRIMARY KEY, ' +
           'DocDate DATETIME, ' +
           'DocClass VARCHAR(20), ' +
           'DocLines BLOB ) '
                      );
     ADOQuery1.ExecSQL;
     ADOQuery1.Close;
end;