ListView without ListActivity

I'm trying to set a Listview under some other Widgets (Buttons, editText, etc). I don't want to use another activity for the listview. After reading some I found How can I implement a ListView without ListActivity? (use only Activity) and I tried to do it, ending up with: Here is my main.xml:

<LinearLayout android:id="@+id/relativeLayout1"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="wrap_content"
android:orientation="vertical">
<TextView ...[some code].../>
<EditText ...[some code].../>
<ImageButton ...[some code].../>
<Chronometer ..[some code]..../>
<ListView android:id="@+id/listView1" android:layout_height="wrap_content"
    android:layout_width="fill_parent"></ListView>

here is my onCreate:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    button1 = (ImageButton) findViewById(R.id.button1);
    mChronometer = (Chronometer) findViewById(R.id.chronometer1);
    editText1 = (EditText) findViewById(R.id.editText1);
    ListView lv = (ListView) findViewById(R.id.listView1);
    String[] listword = new String[] {"Hello","World","Foo","Bar"};
    lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, listword));
    }

and here is list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dp"
android:textSize="16sp" >
</TextView>

When I debug in my physical device, the application simply stays all black. If I comment out the lines of onCreate() that involve the list, the application works (obviously without the listview). Any ideas what might be wrong?