ICCompressorChoose usage?

I am using the vfw.pas unit with Delphi 5, and can get the
ICCompressorChoose function to display the selection dialog, but it shows
only a Full Frames (Compressed) choice.  This is how I am calling the
function:

  m_dwAVIFccHandler := mmioFourCC('D','I','B',' ');
  m_dwAVIQuality := ICQUALITY_DEFAULT;

  CompVar.cbSize := sizeof(TCOMPVARS);
  CompVar.dwFlags := ICMF_COMPVARS_VALID;
  CompVar.fccHandler := m_dwAVIFccHandler;
  CompVar.lQ := m_dwAVIQuality;
  //    CompVar.fccType := ICTYPE_VIDEO;  //creates AV

Success := ICCompressorChoose(Form1.Handle, ICMF_CHOOSE_ALLCOMPRESSORS,
  nil, nil, @CompVar, 'Please Choose Codec');

Could some guru please explain what I am doing wrong?

Thanks!