Custom ListView doesn't save it's state

Question

I was using standart android ListView with simle_list_item_multiple_choice item layout and custom adapter. It saved it's stated on pause and restored on resume. But after few days of working on I've implemented SectionIndexer, StickyListHeadersAdapter interface within my adapter and changed ListView to StickyListHeadersListView from this library. Also there were other changes in application but these are only attached to ListView. However now when my application resumes working listview is coming scrolled to begining and with all items unchecked. I've tryed to remove SectionIndexer interface and sticky headers support but it had no effect. Maybe there is some hidden options of listview which I need to enable?

(tried saveState property - no effect)

public class WordAdapter extends ArrayAdapter<Word> implements SectionIndexer, StickyListHeadersAdapter{
// -----------------------------------------------------------------------
//
// Fields
//
// -----------------------------------------------------------------------
private int mResID;

private List<Word> mList;
private String[] mSectionNames;
private StickyListHeadersListView mListView;
private int[] mSectionIndexes;
private boolean mHeadersEnabled;

// -----------------------------------------------------------------------
//
// Constructor
//
// -----------------------------------------------------------------------
public WordAdapter(Context context, StickyListHeadersListView listView, int resID, List<Word> list, String[] sectionNames, int[] sectionIndexes, boolean enableHeaders) {
    super(context, resID, list);
    mResID = resID;

    mList = list;
    mListView = listView;
    mSectionIndexes = sectionIndexes;
    mSectionNames = sectionNames;

    mHeadersEnabled = enableHeaders;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    if (convertView == null) {
        convertView = LayoutInflater.from(getContext()).inflate(mResID, parent, false);
        holder = new ViewHolder();
        holder.root = convertView;
        holder.textView = (TextView) convertView.findViewById(android.R.id.text1);
        holder.checkBox = (CheckBox) convertView.findViewById(android.R.id.checkbox);

        convertView.setTag(holder);
    }
    holder = (ViewHolder) convertView.getTag();

    holder.textView.setText(getItem(position).getValue());
    if(mListView.isItemChecked(position))
        holder.root.setBackgroundColor(getContext().getResources().getColor(R.color.highlight));
    else
        holder.root.setBackgroundColor(getContext().getResources().getColor(android.R.color.transparent));
    return convertView;
}

@Override
public View getHeaderView(int position, View convertView, ViewGroup parent) {
    if(!mHeadersEnabled)
        return new View(getContext());

    HeaderViewHolder holder;
    if (convertView == null) {
        holder = new HeaderViewHolder();
        convertView = LayoutInflater.from(getContext()).inflate(R.layout.list_item_header, parent, false);
        holder.labelView = (TextView) convertView.findViewById(R.id.list_item_header_label);
        convertView.setTag(holder);
    } else {
        holder = (HeaderViewHolder) convertView.getTag();
    }

    String label;
    if(mSectionNames != null){
        label = mSectionNames[getSectionForPosition(position)];
        holder.labelView.setText(label);
    }
    return convertView;
}

@Override
public long getHeaderId(int position) {
    long result = getSectionForPosition(position);
    return result;
}

@Override
public int getPositionForSection(int section) {
    return (mSectionIndexes == null || section < 0 ) ? 0 : (section == mSectionIndexes.length ? mList.size():mSectionIndexes[section]);
}

@Override
public int getSectionForPosition(int position) {
    if(mSectionIndexes != null && position >= mSectionIndexes[0]) {
        for(int i = 0; i < mSectionIndexes.length; ++i)
            if(position < mSectionIndexes[i])
                return i-1;
        return (mSectionIndexes.length - 1);
    }
    return 0;
}

@Override
public Object[] getSections() {
        return mSectionNames == null ? new Object[0] : mSectionNames; 
}
// -------------------------------------------------------------------------------
//
// Internal classes
//
// -------------------------------------------------------------------------------
private static class ViewHolder {
    public View root;
    public TextView textView;
    public CheckBox checkBox;
}

private static class HeaderViewHolder {
    public TextView labelView;
}

Here is adapter code.