Android custom ListView repeats selection background

I have a custom adapter:

public class PhraseCustomAdapter extends BaseAdapter  
{  
public String original[];  
public String translation[];  
public String transcription[];  

public Activity context;  
public LayoutInflater inflater;  

public PhraseCustomAdapter(Activity context,String[] original, String[] translation, String[] transcription) {  
    super();  

    this.context = context;  
    this.original = original;  
    this.translation = translation;  
    this.transcription = transcription;  

    inflater = LayoutInflater.from(context);
    this.inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);  
}  

@Override  
public int getCount() {  
    // TODO Auto-generated method stub  
    return original.length;  
}  

@Override  
public Object getItem(int position) {  
    // TODO Auto-generated method stub  
     return position;
}  

public String getItemTranlation(int position) {  

    return translation[position];  
}  

public String getItemTranscription(int position) {  
    // TODO Auto-generated method stub  
    return transcription[position];  
}  

public String getItemOriginal(int position) {  
    // TODO Auto-generated method stub  
    return original[position];  
} 


@Override  
public long getItemId(int position) {  
    // TODO Auto-generated method stub  
    return position;  
}  

static class ViewHolder  
{  
    ImageView imgViewLogo;  
    TextView txtViewOriginal;  
    TextView txtViewTranslation;  
    TextView txtViewTranscription; 
}  

@Override  
public View getView(int position, View convertView, ViewGroup parent) {  

    ViewHolder holder;  
    if (convertView == null) {  
        holder = new ViewHolder();  
        convertView = inflater.inflate(R.layout.phrase_row, null);  

        holder.imgViewLogo = (ImageView) convertView.findViewById(R.id.imgViewLogo);  
        holder.txtViewOriginal = (TextView) convertView.findViewById(R.id.txtViewOriginal);  
        holder.txtViewTranslation = (TextView) convertView.findViewById(R.id.txtViewTranslation);  
        holder.txtViewTranscription = (TextView) convertView.findViewById(R.id.txtViewTranscription);   

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


    holder.txtViewOriginal.setText(original[position]);  
    holder.txtViewTranslation.setText(translation[position]);  
    holder.txtViewTranscription.setText(transcription[position]);

    return convertView;  
}   

}

And I need to implement android4-style multi selection (long-press, then click to select item). So:

    lview1 = (ListView) findViewById(R.id.listViewPhrase);  
    adapter = new PhraseCustomAdapter(this, original, translation, transcription);  
    lview1.setAdapter(adapter);  
    lview1.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
    lview1.setMultiChoiceModeListener(new MultiChoiceModeListener() {

        @Override
        public void onItemCheckedStateChanged(ActionMode mode, int position,
                                              long id, boolean checked) {
            View view;
            if (checked){
                Log.v ("checked?", "YES");
                Log.v ("Position", Integer.toString(position));

                view = lview1.getChildAt(position);
                view.setBackgroundColor(Color.LTGRAY);


                original_list.add (adapter.getItemOriginal(position));
                translation_list.add (adapter.getItemTranlation(position));
                transcription_list.add (adapter.getItemTranscription(position));

                countSelected += 1;
            }
            if (!checked){
                Log.v ("checked?", "NO");
                Log.v ("Position", Integer.toString(position));


                for (int i = 0; i < original_list.size(); i++)
                {
                    if (original_list.get(i) == adapter.getItemOriginal(position)){
                        original_list.remove (i);
                        translation_list.remove (i);
                        transcription_list.remove (i);  
                    }
                }
                countSelected -= 1;
            }


            mode.setTitle(Integer.toString(countSelected) + " " + getString(R.string.selectItem));
        }

The problem is: when I long-press the item (for example, first item), the 7th item is highlighted too (by changing background). When I try to "unhighlight" highlighted 7th item, app crashes. If I try to click the latest item, app crashes. I have read some articles about how View is rendered and recycle items, but I don't know any possible solution for my problem

UPD: LogCat output when "unhighlighting" 7th item:

    V/checked?(24966): YES
V/Position(24966): 7
Shutting down VM
threadid=1: thread exiting with uncaught exception (group=0x2b542210)
AndroidRuntime(24966): FATAL EXCEPTION: main
java.lang.NullPointerException
at com.alextee.phrases.PhraseActivity$1.onItemCheckedStateChanged(PhraseActivity.java:145)
at android.widget.AbsListView$MultiChoiceModeWrapper.onItemCheckedStateChanged(AbsListView.java:5688)
at android.widget.AbsListView.performItemClick(AbsListView.java:1040)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:2522)
at android.widget.AbsListView$1.run(AbsListView.java:3183)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
 android.app.ActivityThread.main(ActivityThread.java:4441)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)