ListView:convertView/holder混淆

有人能看到我在下面的代码中做错了什么吗?

static LinearLayout.LayoutParams layoutParams;
(...)

public View getView(int position, View convertView, ViewGroup parent){
    ReferenceHolder holder;

    if (convertView == null){
        convertView = inflater.inflate(R.layout.pick_image_row, null);
        holder = new ReferenceHolder();
        holder.getIdsAndSetTag(convertView, position);
        if (data[position][ORIENTATION] == LANDSCAPE) {
            // Layout defaults to portrait settings, so ImageView size needs adjusting. 
            // layoutParams is modified here, with specific values for width, height, margins etc
            holder.image.setLayoutParams(layoutParams);
        }
        holder.orientation = data[position][ORIENTATION];

    } else {
        holder = (ReferenceHolder) convertView.getTag();
        if (holder.orientation != data[position][ORIENTATION]){  //This is the key if statement for my question
            switch (image[position][ORIENTATION]) {
            case PORTRAIT:
                // layoutParams is reset to the Portrait settings
                holder.orientation = data[position][ORIENTATION];
                break;

            case LANDSCAPE:
                // layoutParams is reset to the Landscape settings
                holder.orientation = data[position][ORIENTATION];
                break;
            }
            holder.image.setLayoutParams(layoutParams);
        }               
    }

    // and the row's image and text is set here, using holder.image.xxx
    // and holder.text.xxx

    return convertView;
}

static class ReferenceHolder {
    ImageView image;
    TextView text;
    int orientation;

    void getIdsAndSetTag(View v, int position){
        image = (ImageView) v.findViewById(R.id.pickImageImage);
        text = (TextView) v.findViewById(R.id.pickImageText);
        orientation = data[position][ORIENTATION];
        v.setTag(this);
    }
}

谢谢!