title: ClassCastException with findFragmentById
body: <p>I try to get a specific Fragment with:</p>
  
  <pre><code>RohwareFragmentMatlist fragment =    (RohwareFragmentMatlist)getFragmentManager().findFragmentById(R.id.lagerfragment);
  </code></pre>
  
  <p>But I get an error from eclipse with this message: </p>
  
  <blockquote>
    <p>Cannot cast from Fragment to RohwareFragmentMatlist</p>
  </blockquote>
  
  <p>The Activity starts with:</p>
  
  <pre><code>public class RohwareActionBar extends FragmentActivity {...
  </code></pre>
  
  <p>The RohwareFragmentMatlist is defined as follows:</p>
  
  <pre><code>public class RohwareFragmentMatlist extends ListFragment
          implements LoaderManager.LoaderCallbacks&lt;Cursor&gt;{...
  </code></pre>
  
  <p>The Fragment is defined this way:</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="horizontal"
  android:layout_width="match_parent" 
  android:layout_height="match_parent"&gt;
  
  &lt;fragment
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:name="de.ypssoft.RohwareFragmentMatlist"
  android:layout_weight="1"
  android:layout_width="0px" 
  android:layout_height="match_parent"
  android:id="@+id/lagerfragment" 
  android:layout_margin="5dip" 
  android:layout_marginLeft="10dip"
  &gt;
  &lt;/fragment&gt;
  &lt;FrameLayout 
  android:id="@+id/details" 
  android:layout_weight="3"
  android:layout_width="0px" 
  android:layout_height="match_parent"
   android:background="?android:attr/detailsElementBackground" /&gt; 
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>Doesn't it work to get a Fragment via "getFragmentById" using ListFragment?</p>