CheckedTextView - Einträge werden nicht selektiert

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:paddingTop="4dip"
     android:paddingBottom="6dip"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
     android:orientation="vertical"
     >

<LinearLayout
   android:layout_width="310dip"
   android:layout_height="wrap_content"
   android:layout_weight="10"
   android:orientation="horizontal">
     
<LinearLayout
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_weight="9"
   android:orientation="vertical">     
 
     <TextView android:id="@+id/auf_datum"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginBottom="8dip"/>
 
     <TextView android:id="@+id/auf_inhalt"
         android:layout_width="wrap_content"
         android:layout_marginBottom="8dip"
         android:layout_height="wrap_content" 
         android:layout_weight="1"/>

 <LinearLayout
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_weight="1"
   android:orientation="horizontal">
     
     <TextView android:id="@+id/auf_termin"
         android:layout_width="60dip"
         android:layout_height="wrap_content"  
         android:layout_weight="1"/>
      
      <TextView android:id="@+id/auf_preis"
         android:layout_width="60dip"
         android:layout_height="wrap_content" 
         android:layout_weight="1"/>   
         
     </LinearLayout>
  
  </LinearLayout>

 <LinearLayout
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_weight="1"
   android:orientation="vertical">
   
 <CheckedTextView
  android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/auf_check"
 android:layout_marginRight="10dip"
 android:layout_marginTop="15dip"
 android:layout_marginLeft="10dip"
  android:checkMark="?android:attr/listChoiceIndicatorMultiple"
 android:clickable="true"
 />  
   
 
</LinearLayout> 
</LinearLayout>              
</LinearLayout>

ListView list = getListView();
      list.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
       
      SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
          R.layout.checked_text_view, 
          c, 
          new String[] { "_id", "bemerkung", "termin", "preis"  }, 
          new int[]{R.id.auf_datum,R.id.auf_inhalt,R.id.auf_termin,R.id.auf_preis} );
      
      adapter.setViewBinder(new ViewBinder() {
      // Daten werden in die einzelnen TextViews geladen.
});
      setListAdapter(adapter);

//der Listener:

 protected void onListItemClick(ListView l, View v, int position, long id) {
  		super.onListItemClick(l, v, position, id);
  		Intent i = new Intent(Activity1.this, Activity2.class);
                startActivity(i);
}