my checkbox doesn't seem instanceof CheckBox

Working on my thesis I'm gettin a warning in LogCat that I think might affect my code.

I receive a JSON with some data and I have to bild a layout with checkbox and radiobutton (in RadioGroup) programmatically. Later I can vote this survey and here is my problem cause when I getChildAt() in my layout

if(child instanceof CheckBox)

doesn't work and I can't understand why.

Here is my code:

 ll = (LinearLayout) findViewById(R.id.llSurvey);  //OnCreate

    /*Creating CheckBox*/
            String votes = jObj.getString("votes");
            String label = jObj.getString("label");
            String usid = jObj.getString("USID");    
            if(uType.equals("multi")){
                CheckBox cb = new CheckBox(SingleSurvey.this);
                cb.setText(label + " (" + votes + ")");
                cb.setId(s+1000);
                ll.addView(cb);         
                Log.i("MULTI_TYPE", "usid: " + usid + " id: " + cb.getId());
            }
            s++;

    /*Voting*/
    LinearLayout llvs = (LinearLayout) findViewById(R.id.llSurvey);

            for(int i = 0; i < llvs.getChildCount(); i++){
                View child = llvs.getChildAt(i);
                int p = child.getId();
                Log.i("CHILD ID", "id: " + p);

                if(child instanceof TextView){
                    continue;
                }

                else if(child instanceof CheckBox){
                    Log.i("INSTANCE OF CB", "usid: " + usid);
                    CheckBox cb = (CheckBox) child;
                    if(cb.isChecked()){
                        Log.i("CHECKBOX", "usid: " + usid);
                        int cbId = cb.getId();
                        usid = rb_usid[cbId];
                    }
                }

                //some other stuff
            }