Android recyclerview content changes in onscroll

I am using a RecyclerView to display a list and every item in the RecyclerView is displayed as a CardView. When the RecyclerView is scrolled, the content inside the CardView changes.

Before scrolling down: After scrolling down:

 

As you can see above, the two "UNKNOWN" images have been changed to "null". The content displayed inside the RecyclerView is retrieved from SQLite. Couldn't find any solution after hours of surfing the web.

Adapter class:

 public class DraftListAdapter extends
RecyclerView.Adapter<DraftListAdapter.ViewHolder> {

    private static final String TAG = "DraftListAdapter";

    private ArrayList<EventDAO> al_item_list;

    private int rowLayout;

    private Activity obj_activity;

    private DisplayImageOptions obj_display_image_options;

    private static RecyclerViewClickListener itemListener;

    private SimpleDateFormat obj_date_formater_display = new SimpleDateFormat(
            "MMMM d, yyyy");
    private SimpleDateFormat obj_date_formater_sqlite = new SimpleDateFormat(
            "yyyy-MM-dd");

    public DraftListAdapter(ArrayList<EventDAO> al_item_list, int rowLayout,
            Activity obj_activity, DisplayImageOptions obj_display_image_options) {

        this.al_item_list = al_item_list;
        this.rowLayout = rowLayout;
        this.obj_activity = obj_activity;
        this.obj_display_image_options = obj_display_image_options;
    }

    public DraftListAdapter(ArrayList<EventDAO> al_item_list, int rowLayout,
            Activity obj_activity,
            DisplayImageOptions obj_display_image_options,
            RecyclerViewClickListener itemListener) {

        this.al_item_list = al_item_list;
        this.rowLayout = rowLayout;
        this.obj_activity = obj_activity;
        this.obj_display_image_options = obj_display_image_options;
        this.itemListener = itemListener;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {

        View v = LayoutInflater.from(viewGroup.getContext()).inflate(rowLayout,
                viewGroup, false);

        return new ViewHolder(v);
    }

    @Override
    public void onBindViewHolder(final ViewHolder viewHolder, final int position) {

        final EventDAO obj_current = al_item_list.get(position);

        viewHolder.button_edit.setText("EDIT");

        viewHolder.imageview_bookmark.setVisibility(View.INVISIBLE);
        viewHolder.imageview_call.setVisibility(View.INVISIBLE);

        //display event banner
        viewHolder.imageview_event_banner.setTag(position);
        viewHolder.textview_event_name.setTag(position);

        ImageLoader.getInstance().displayImage("file:///"+obj_current.eventBanner,
                viewHolder.imageview_event_banner, obj_display_image_options,null);

        viewHolder.imageview_event_banner.setAlpha(200);

        //display event location slug
        viewHolder.textview_event_name.setText(obj_current.eventName);

        if (obj_current.isOnline.equals("1")) {
            viewHolder.linearlayout_location.setVisibility(View.GONE);
            viewHolder.linearlayout_online.setVisibility(View.VISIBLE);
            viewHolder.textview_location_slug.setText("ONLINE EVENT");
        } else {

            viewHolder.linearlayout_location.setVisibility(View.VISIBLE);
            viewHolder.linearlayout_online.setVisibility(View.GONE);
            if(obj_current.objLocation != null 
                    && obj_current.objLocation.locationName != null
                    && !obj_current.objLocation.locationName.equalsIgnoreCase(""))
                viewHolder.textview_location_slug.setText(obj_current.objLocation.locationName);

        }

        //display date
        //display time
        viewHolder.textview_event_time.setText("Time: " + obj_current.startTime);
        viewHolder.button_edit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                Fragment obj_fragment = CreateEventFragment.newInstance(obj_current);

                FragmentTransaction fragment_transaction_eventdetails = ((MainActivity) obj_activity)
                        .getSupportFragmentManager().beginTransaction();

                // Get the details of that view to the EventDetailsFragment..
                fragment_transaction_eventdetails.replace(R.id.container,
                        obj_fragment);


                fragment_transaction_eventdetails.addToBackStack(obj_fragment
                        .getClass().getName());

                fragment_transaction_eventdetails.commit();

            }
        });


        viewHolder.button_delete.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                new AlertDialog.Builder((MainActivity) obj_activity)
                .setTitle("Quit")
                .setMessage("Do you really want to delete this drafted event?")
                .setPositiveButton("Yes",
                        new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog,
                            int which) {
                        EventDAO obj_delete_event_dao = new EventDAO(obj_activity);
                        obj_delete_event_dao.deleteEvent(obj_current.localEventID);
                        obj_delete_event_dao.closeDbConnection();
                        al_item_list.remove(position);
                        notifyDataSetChanged();
                    }
                }).setNegativeButton("No", null).show();
            }
        });

        viewHolder.linearlayout_location
        .setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                Toast.makeText(obj_activity, "Map intent",
                        Toast.LENGTH_SHORT).show();

                Intent intent = new Intent(Intent.ACTION_VIEW, Uri
                        .parse("geo:0,0?q=Kothrud"));

                obj_activity.startActivity(Intent.createChooser(intent,
                        "Select "));
            }
        });

    }

    @Override
    public int getItemCount() {
        return al_item_list == null ? 0 : al_item_list.size();
    }

    /**
     * class to hold event list item
     * 
     * 
     */
    public static class ViewHolder extends RecyclerView.ViewHolder implements
    OnClickListener {

        public ImageView imageview_event_banner;
        public ImageView imageview_bookmark;
        public ImageView imageview_call;

        public TextView textview_event_name;
        //      public TextView textview_event_type;
        public TextView textview_location_slug;
        public TextView textview_event_date;
        public TextView textview_event_time;
        public Button button_edit;
        public Button button_delete;
        public LinearLayout linearlayout_location;
        public LinearLayout linearlayout_online;

        public ViewHolder(View itemView) {
            super(itemView);

            linearlayout_location = (LinearLayout) itemView
                    .findViewById(R.id.linearlayout_location);

            linearlayout_online = (LinearLayout) itemView
                    .findViewById(R.id.linearlayout_online);

            imageview_event_banner = (ImageView) itemView
                    .findViewById(R.id.imageview_event_banner);

            imageview_bookmark = (ImageView) itemView
                    .findViewById(R.id.imageview_bookmark);

            imageview_call = (ImageView) itemView
                    .findViewById(R.id.imageview_call);

            textview_event_name = (TextView) itemView
                    .findViewById(R.id.textview_event_name);
            textview_event_name.setSelected(true);

            textview_location_slug = (TextView) itemView
                    .findViewById(R.id.textview_location_slug);

            textview_location_slug.setSelected(true);

            textview_event_date = (TextView) itemView
                    .findViewById(R.id.textview_event_date);

            textview_event_time = (TextView) itemView
                    .findViewById(R.id.textview_event_time);

            button_edit = (Button) itemView
                    .findViewById(R.id.button_edit);
            button_delete = (Button) itemView
                    .findViewById(R.id.button_delete);

            linearlayout_location.setOnClickListener(this);

            itemView.setOnClickListener(this);
        }

        @Override
        public void onClick(View v) {

            itemListener.recyclerViewListClicked(v, getPosition());

        }
    }

}