StringGrid утопление шапки при нажатии

class TForm1 : public TForm
{
__published:    // IDE-managed Components
    // ...
 
private:    // User declarations
public:     // User declarations
    __fastcall TForm1(TComponent* Owner);
 
    void __fastcall DrawHeader(HDC hdc, TRect R, String s, bool pressed = false); // Добавляем вот это
};

// Реализации
void __fastcall TForm1::DrawHeader(HDC hdc, TRect R, String s, bool pressed)
{
    R.Right += (pressed ? 0 : 1); R.Bottom += (pressed ? 0 : 1);
    DrawFrameControl(hdc, &R, DFC_BUTTON, DFCS_BUTTONPUSH | (pressed ? DFCS_PUSHED : 0));
    R.Right += (pressed ? 1 : -1); R.Bottom += (pressed ? 1 : -1);
    SetBkMode(hdc, TRANSPARENT);
    DrawText(hdc, s.c_str(), s.Length(), &R, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
}
 
void __fastcall TForm1::StringGrid1MouseDown(TObject *Sender, TMouseButton Button,
          TShiftState Shift, int X, int Y)
{
    int Col, Row;
 
    TStringGrid* grid = dynamic_cast<TStringGrid*>(Sender);
    grid->MouseToCell(X, Y, Col, Row);
    if(Row == 0)
    {
        TRect R = grid->CellRect(Col, Row);
        DrawHeader(grid->Canvas->Handle, R, grid->Cells[Col][Row], true);
    }
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::StringGrid1MouseUp(TObject *Sender, TMouseButton Button, TShiftState Shift,
          int X, int Y)
{
    int Col, Row;
 
    TStringGrid* grid = dynamic_cast<TStringGrid*>(Sender);
    grid->MouseToCell(X, Y, Col, Row);
    if(Row == 0)
    {
        TRect R = grid->CellRect(Col, Row);
        DrawHeader(grid->Canvas->Handle, R, grid->Cells[Col][Row]);
    }
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::StringGrid1DrawCell(TObject *Sender, int ACol, int ARow, TRect &Rect,
          TGridDrawState State)
{
    if(State.Contains(gdFixed))
    {
        TStringGrid* grid = dynamic_cast<TStringGrid*>(Sender);
        DrawHeader(grid->Canvas->Handle, Rect, grid->Cells[ACol][ARow]);
    }
}

void __fastcall TForm1::FormCreate(TObject *Sender)
{
    StringGrid1->Cells[1][0] = "Column 1";
    StringGrid1->Cells[2][0] = "Column 2";
    StringGrid1->Cells[3][0] = "Column 3";
    StringGrid1->Cells[4][0] = "Column 4";
    StringGrid1->Cells[5][0] = "Column 5";
}

 SetBkMode(hdc, TRANSPARENT);

SetTextColor(hdc, 0x00000000);