Артефакты прозрачности при отображении TBitmap(подгруженного из png-ресурса) в строчках TPopupMenu.

    TMenuItem *tmp_mi = tmp->popup_menu->Items;
    String action_name_str;
    TPngImage *tmp_png = new TPngImage( );
    tmp_png->Transparent = true;
    for ( int i = 0, img_list_index = 2; i < 9; i++, img_list_index += 2 ) {
        action_name_str = tmp->img_list->Strings[img_list_index];
        tmp_mi->Items[i]->Name = tmp->Name + "_" + action_name_str + "_ppmi";
 
        tmp_png->LoadFromResourceName( ( int )HInstance, action_name_str );
        tmp_mi->Items[i]->Bitmap = new Graphics::TBitmap( );
        tmp_mi->Items[i]->Bitmap->Assign( tmp_png );
        tmp_mi->Items[i]->Bitmap->Transparent = true;
        tmp_mi->Items[i]->Bitmap->TransparentMode = tmAuto;
        //...

tmp_mi->Items[i]->Bitmap = new Graphics::TBitmap( );

Graphics::TBitmap *B = new Graphics::TBitmap(); 
tmp_mi->Items[i]->Bitmap->Assign(B);
delete B;

    sth_btn_ppmenu_img_lst = new TImageList( this );
    sth_btn_ppmenu_img_lst->ColorDepth = cd32Bit;
    sth_btn_ppmenu_img_lst->SetSize( 16, 16 );
    Graphics::TBitmap *bmp = new Graphics::TBitmap( );
    tmp->popup_menu->Images = sth_btn_ppmenu_img_lst;
    TMenuItem *tmp_mi = tmp->popup_menu->Items;
    String action_name_str;
    TPngImage *tmp_png = new TPngImage( );
    tmp_png->Transparent = true;
    for ( int i = 0, img_list_index = 2; i < 9; i++, img_list_index += 2 ) {
        action_name_str = tmp->img_list->Strings[img_list_index];
        tmp_mi->Items[i]->Name = tmp->Name + "_" + action_name_str + "_ppmi";
 
        tmp_png->LoadFromResourceName( ( int )HInstance, action_name_str );
        bmp->Assign( tmp_png );
        tmp_mi->Items[i]->ImageIndex = sth_btn_ppmenu_img_lst->Add( bmp, NULL );
        //...