display tooltips on CListCtrl items

< NOTE : this a repost of a question that I posted earlier on 18/6; the first question got the status PAQ, but in fact it was not answered >

I have written a CListBoxEx class, derived from CListCtrl. It's designed as a replacement for the standard CListBox, very easy to use, but with all the extras of CListCtrl, if needed.
One of the extras I want is to display tooltips giving additionnal information on the item under the mouse cursor. I found a way, it works fine under Windows 95, BUT NOT UNDER WINDOWS NT (no tooltip appears under NT).
I'm a lazy programmer, I don't have the time and even less the desire to learn all the low level subtilities of Windows event routing, experts are there for such things ... please give me quick (& dirty) advice, I pay cash !

Below are extracts of my code concerning tooltips :

////// code in a dialogbox using a CListBoxEx listbox

BOOL CSAPDlg::OnInitDialog()
{
// creation of a CToolTipCtrl control :
m_toolTip.Create( this, TTS_ALWAYSTIP );
m_toolTip.Activate(TRUE);
...
// registering the tooltip in the m_ListSendLic listbox, which is a CListBoxEx :
m_ListSendLic.RegisterTooltip   (&m_toolTip, this, IDC_LIST_SENDLIC);
...
}

BOOL CSAPDlg::OnToolTipNeedText( UINT id, NMHDR* pNMHDR, LRESULT* pResult )
{
TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;    
if (! (pTTT->uFlags & TTF_IDISHWND) )    
       switch( pNMHDR->idFrom)
// here get the current item for the listbox identified by pNMHDR->idFrom,
// and fill the tooltip's text buffer with relevant information for this item.
}

////// code in the CListBoxEx class

BEGIN_MESSAGE_MAP(CListBoxEx, CListCtrl)
 //{{AFX_MSG_MAP(CListBoxEx)
 ON_WM_MOUSEMOVE()
 ON_NOTIFY_EX( TTN_NEEDTEXT, 0, OnToolTipNeedText )
 //}}AFX_MSG_MAP
END_MESSAGE_MAP()

void CListBoxEx::RegisterTooltip (CToolTipCtrl *pToolTip, CWnd *pParentWnd, long ID)
{
 m_pToolTip = pToolTip;
 m_pParentWnd = pParentWnd;
 RECT rect;
 m_toolTipID = ID;
 pToolTip->AddTool( this,  LPSTR_TEXTCALLBACK, &rect, ID);
}

void CListBoxEx::OnMouseMove(UINT  nFlags, CPoint point)
{
 CListCtrl::OnMouseMove(nFlags, point);
 int index = HitTest(point);
 if (index != m_MouseIndex)
 // if item under cursor has changed since last call :
 {
  m_MouseIndex = index;
  if (m_pToolTip)
  {
   RECT rect;
   GetItemRect( index, &rect, LVIR_BOUNDS); // rect = rectangle surrounding item under cursor
   m_pToolTip->SetToolRect( this, m_toolTipID, &rect);// new rectangle for the tooltip control --> force call to OnToolTipNeedText
  }
 }
}

BOOL CListBoxEx::PreTranslateMessage(MSG* pMsg)
{
 switch( pMsg->message )
  {
   case WM_LBUTTONDOWN:
   case WM_MOUSEMOVE:
   case WM_LBUTTONUP:
   case WM_RBUTTONDOWN:
   case WM_RBUTTONUP:
   case WM_MBUTTONDOWN:
   case WM_MBUTTONUP:
    if (m_pToolTip)
     m_pToolTip->RelayEvent(pMsg);
    break;
  }
 return CListCtrl::PreTranslateMessage(pMsg);
}

BOOL CListBoxEx::OnToolTipNeedText( UINT id, NMHDR* pNMHDR, LRESULT* pResult )
{
 if (m_pParentWnd)
  m_pParentWnd->SendMessage(WM_NOTIFY, 0, (long) pNMHDR);
 return TRUE;
}