Programmatically adding Bitmap images to ImageList using Add method

I'm trying to dynamically fill an ImageList with png icons stored in a database. Afterwards, that ImageList will be linked to an ImageComboBox and the icons displayed.

I'm sure the save and load from the database is working just fine, because I checked the temporary file created by the code below. However the problem is on adding images to the ImageList. After that cycle that keeps creating and adding Bitmaps to the ImageList I check the Count field and it has 0 items!!

What am I missing? What doesn't the ImageList.Add() properly work? I tried with and without a bitmap mask and got the same problem.

Delphi
...  
items.Clear; index := 0;  
while not Eof do  
begin  
  // Table (blob) to File  
  tmpIconFilename := FieldByName('IdIcon').AsString + '.png';  
  tmpIconFilepath := ExtractFilePath(Application.ExeName) + tmpIconFilename;  
  blobIcon := FieldByName('Icon32') as TBlobField;  
  blobIcon.SaveToFile(tmpIconFilepath);  
  // File to Stream  
  streamIcon := TMemoryStream.Create;  
  tmpFileIcon := TPngImage.Create;  
  tmpFileIcon.LoadFromFile(tmpIconFilename);  
  tmpFileIcon.SaveToStream(streamIcon);  
  DeleteFile(tmpIconFilename);  
  // Stream to Bitmap  
  bitmapIcon := TBitmap.Create;  
  bitmapIcon.LoadFromStream(streamIcon);  

  // Bitmap to ImageList  
  maskIcon := TBitmap.Create;  
  maskIcon.Assign(bitmapIcon);  
  maskIcon.Canvas.Brush.Color := clNone; //bkg color  
  maskIcon.Monochrome := true;  
  imagelistNotifPosIcon.Add(bitmapIcon, maskIcon);  

  // Add (icon) item to (icon) combobox  
  Item := Items.Add as TcxImageComboBoxItem;  
  Item.Value := FieldByName('IdIcon').AsString;  
  Item.Description := FieldByName('IdIcon').AsString;  
  Item.ImageIndex := index;  

  index := index + 1;  
  Next;  
end;  

ShowInfoMsg('ImageList count: ' + IntToStr(imagelistNotifPosIcon.Count));  

Help is much appreciated.