I found here and here similar issues, but the problem is slightly different.
In a ListView, I try to put an adapter (extends from base Adapter) which contents checkbox.
List view layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    style="@style/mainLayout"
 >
    <Button
        android:id="@+id/close_cat"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="buttonClick"
        android:text="@string/back" />
    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />
</LinearLayout>
XML of list's elements:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >
    <TableLayout
        android:id="@+id/blocCheck"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="25px"
        android:layout_marginTop="25px"
        android:background="@color/black" >
        <TableRow
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:baselineAligned="true"
            android:paddingLeft="4sp" >
            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center_vertical"
                android:layout_weight="1"
                android:orientation="horizontal"
                android:paddingLeft="20sp" >
                <ImageView
                    android:id="@+id/iv_cat"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
                <TextView
                    android:id="@+id/category"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="left"
                    android:layout_marginLeft="15dip"
                    android:text="tfgldkjhglf"
                    android:textSize="20sp" />
            </LinearLayout>
            <CheckBox
                android:id="@+id/check_cat"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="right"
                android:layout_marginRight="10sp"
                android:onClick="MyHandler" />
        </TableRow>
    </TableLayout>
</LinearLayout>
I set adapter in my view :
list = getListView();
list.setAdapter(new CatAdapter(this, listCat));
My adapter:
public class CatAdapter extends BaseAdapter {
    private LayoutInflater  mInflater;
    private List<CatAdapterObject> mListAppInfo;
    private Context mContext;
    /**
     * Constructor
     * @param context
     * @param data
     * @param resource
     * @param from
     * @param to
     */
    public CatAdapter (Context context, List<CatAdapterObject> list){   
        mContext = context;
        mListAppInfo = list;
        mInflater = LayoutInflater.from(mContext);      
    }
    /**
     * number of elements
     */
    @Override
    public int getCount() {
        return mListAppInfo.size();
    }
    /**
     * get an item in the list
     */
    @Override
    public Object getItem (int position){
        return mListAppInfo.get(position).getId();
    }
    /**
     * get id of the selected item
     */
    @Override
    public long getItemId(int position) {
        return mListAppInfo.get(position).getId();
    }
    /**
     * get the view
     */
    @Override
    public View getView (int position, View convertView, ViewGroup parent){
        LinearLayout layoutItem;
        if (convertView == null) {
            layoutItem = (LinearLayout) mInflater.inflate(R.layout.category,    parent, false);
        } else {
            layoutItem = (LinearLayout) convertView;
        }
        // get the current category
        CatAdapterObject entry =  mListAppInfo.get(position);
        //view setting
        TextView category = (TextView) layoutItem.findViewById(R.id.category);
        CheckBox cb         = (CheckBox) layoutItem.findViewById(R.id.check_cat);
        ImageView iv_cat    = (ImageView) layoutItem.findViewById(R.id.iv_cat);
        //elements setting
        category.setText(entry.getName());
        //checkbox
        cb.setChecked(entry.isChecked());
        cb.setTag(position);
        //picture
        Bitmap icon = Utils.getResizedBitmap(BitmapFactory.decodeResource(mContext.getResources(),entry.getPict()),45,45,true);     
        iv_cat.setImageBitmap(icon);
        return layoutItem;
    }
}
When activity is lauched, list is displayed perfectly. I can scroll up/down without any problem. However, when I check one of the checkboxes and scroll down, box which was checked "loose" its check mark and the background color of the latest box in the list changed.
When checking a box, below method is called (In my activity file):
public void MyHandler(View v) {
        //クリックされたcheckbox
        cb = (CheckBox) v;
        Log.d("CHECKBOX","before :"+Utils.implode(",",this.cat_id_list));
        //get position in the list
        Integer position = Integer.parseInt(cb.getTag().toString());
        //instance of the view (list's child)
        View o = list.getChildAt(position).findViewById(R.id.blocCheck);
        // check if box is checked
        if (cb.isChecked()) { 
            o.setBackgroundResource(R.color.pink);
            this.cat_id_list.add(position.toString());
        // 背景色を替え、リストから削除
        } else { 
            o.setBackgroundResource(R.color.black);
            Collections.sort(this.cat_id_list);
            int index = Collections.binarySearch(this.cat_id_list,position.toString());
            this.cat_id_list.remove(index);
        }
        Log.d("CHECKBOX","after :"+Utils.implode(",",this.cat_id_list));
    }
There are 8 elements in my list but when I check the "mChildrenCount" of the list, there are only 5 elements.
I just want to save in the "this.cat_id_list" id of elements wich were checked and change background color of selected item.
I would appreciate your help !