Android : android layout weight creates gap

I am new to android developing. I try to iterate through a Hashmap to create vertical linear layouts which always include one ImageView and one Button. This works fine so far. To allocate the available space equal to all linear layouts i try to use the weight attribute. This also works. But unfortunately it creates a huge gap vertically between the Image and the button. I dont understand why. Any Idea?

Iterator it = map.entrySet().iterator();
        while (it.hasNext()) {
            Map.Entry pair = (Map.Entry)it.next();
            if(count%3==0){
                if(linear!=null){
                    layout.addView(linear);
                }
                linear=new LinearLayout(getApplicationContext());
                linear.setOrientation(LinearLayout.HORIZONTAL);
                linear.setLayoutParams(layoutParams);
            }
            LinearLayout linear2=new LinearLayout(getApplicationContext());
            LinearLayout.LayoutParams lp1 = new LinearLayout.LayoutParams(0, 
                    LinearLayout.LayoutParams.WRAP_CONTENT, 1f);
            lp1.setMargins(15, 0, 15, 0);
            linear2.setLayoutParams(lp1);
            linear2.setOrientation(LinearLayout.VERTICAL);
            final String finalstring=(String)pair.getKey();
            Button button = new Button(getApplicationContext());
            button.setText((String)pair.getKey());
            button.setClickable(false);
            button.setBackgroundColor(getResources().getColor(R.color.friking_blue));

            ImageView image = new ImageView(getApplicationContext());
            new DownloadImageTask(image).execute((String)pair.getValue());

            linear2.addView(image);
            linear2.addView(button);
            linear.addView(linear2);
            linear2.setOnClickListener(new View.OnClickListener(){
                public void onClick(View v){
                    Intent intent = new Intent(getApplicationContext(), Mycontacts.class);
                    intent.putExtra("category", finalstring);
                    startActivity(intent);
                }
            });
            count++;
            it.remove(); // avoids a ConcurrentModificationException
        }

Since I am not allowed to post images i will just post the Link.

Link to image

Thanks for any help!