Focus problem during a right click in the windows system tray

In response to which message and using which function is the popup menu shown?

In response to which message and using which function is the popup menu shown?

I have this function that catches the message where WM_SYSTEMTRAYICON is the uCallbackMessage of the system tray.

LRESULT CALLBACK WndProcMain (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch(message)
{
case WM_SYSTEMTRAYICON:
{
return(SystemTrayIcon.TrayIconMsgProc(wParam, lParam));
}
case WM_DESTROY:
{
PostQuitMessage (0);
return (0);
}
}
return (DefWindowProc (hwnd, message, wParam, lParam));
}

So there we call the function TrayIconMsgProc that then shows up the popup menu.

LRESULT CSystemTrayIcon::TrayIconMsgProc(WPARAM wParam, LPARAM lParam)
{
//check if the message is for this tray icon
if(wParam != m_pIconData->uID)
return(0L);

//if the right mouse button was clicked, we show the popup menu at the current mouse pointer location
if(lParam == WM_RBUTTONDOWN)
{
if(m_hPopupMenu == NULL)
return 0L;

POINT CursorPos;

//we need to set a foreground window so that the menu is closed after the
//window looses the focus
SetForegroundWindow(m_pIconData->hWnd);

if(GetCursorPos(&CursorPos))
TrackPopupMenu(m_hPopupMenu, TPM_RIGHTBUTTON, CursorPos.x, CursorPos.y, 0, m_pIconData->hWnd, NULL);
}

return(0L);
}

Maybe there is some mistake in the function showing up the popup menu, but I'm quite stuck.

Thanks in advance!

PS: No, I'm not using anything like Google toolbar or Google Desktop.

Yes. Context menus should be shown on releasing the right mouse button or menu keyboard key.