ExpandableListView uncheck all checkboxes - NOT WORKING

    ExpListView.setOnChildClickListener(new OnChildClickListener() {

        @Override
        public boolean onChildClick(ExpandableListView parent, View v,
                int groupPosition, int childPosition, long id) {
            MyListAdapter adapter = (MyListAdapter) parent
                    .getExpandableListAdapter();

            for (int i = 0; i < adapter.getChildrenCount(groupPosition); i++) {
                View view2 = (View) adapter.getChildView(groupPosition, i,
                        false, v, parent);
                CheckBox cb2 = (CheckBox) view2.findViewById(R.id.checkbox);
                cb2.setChecked(false);
            }
            parent.invalidateViews(); // Update the list view

            CheckBox cb = (CheckBox) v.findViewById(R.id.checkbox);
            cb.setChecked(true);
            return false;
        }
    });