Listview touch event highlights the wrong element

Question

I have a customised listview in an activity. The listview row item has a custom layout, with two text assets and one button.

The list is populated correctly and I am able to click the buttons without activating the actual item row, using '"android:descendantFocusability="blocksDescendants"' in the item layout.

But when I an tapping the different rows, I get weird hightlighting.

The list has two entries. Tapping on the main row for item #1 hightlights the entire row, fine. Tapping the button highlights the button, again fine.

But tapping the main row for item #2, the button in that row is hightlighted, not the row item itself. Tapping the button also hightlights the button, as normal.

So why isnt the #2 row being highlighted when tapped?

Activity (there is a parent RelativeView):

<ListView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/screenListView"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

ListView Item:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:descendantFocusability="blocksDescendants" >

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Text"
    android:id="@+id/name"
    android:layout_margin="5dp"
    android:layout_alignParentLeft="true"
    android:textSize="16sp" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Text"
    android:id="@+id/playlist"
    android:textSize="12sp"
    android:layout_margin="5dp"
    android:layout_below="@+id/name"
    android:layout_alignParentLeft="true" />

<ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/playButton"
    android:src="@drawable/ic_action_play"
    android:layout_alignParentRight="true" />

</RelativeLayout>

Adapter:

public class ScreenListViewAdapter extends ArrayAdapter<ScreenModel> {

private final Context context;
private final ArrayList<ScreenModel> optionsArrayList;

public ScreenListViewAdapter(Context context, ArrayList<ScreenModel> optionsArrayList) {

    super(context, R.layout.playlist_list_item, optionsArrayList);

    this.context = context;
    this.optionsArrayList = optionsArrayList;
}

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

    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    View rowView = inflater.inflate(R.layout.screen_list_item, parent, false);

    if (position % 2 == 1) {
        rowView.setBackgroundColor(context.getResources().getColor(R.color.list_row_colour_1));
    }

    rowView.setTag(optionsArrayList.get(position).getPlaylistId());

    TextView name = (TextView) rowView.findViewById(R.id.name);
    TextView playlistName = (TextView) rowView.findViewById(R.id.playlist);
    ImageButton playBtn = (ImageButton) rowView.findViewById(R.id.playButton);

    playBtn.setTag(optionsArrayList.get(position).getPlaylistId());

    name.setText(optionsArrayList.get(position).getName());
    playlistName.setText(optionsArrayList.get(position).getPlaylistName());

    // handle "play" button
    playBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            // do stuff
        }
    });

    return rowView;
}