Layout änderung bringt App zum Crash

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/black"
    android:gravity="center|bottom" 
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_weight="1"
        android:layout_height="0dp" 
        android:layout_marginBottom="@dimen/activity_vertical_margin">

        <TextView
            android:id="@+id/textViewTags"
            android:textColor="@color/darkersilver"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="@string/empty"
            android:textAppearance="?android:attr/textAppearanceLarge" >            
        </TextView>        
    </LinearLayout>
        
    <LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
        android:orientation="vertical" >
                
        <ProgressBar
            android:id="@+id/progressBarPeakL"
            style="?android:attr/progressBarStyleHorizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="4dp"
            android:max="32767"
            android:progress="0"
            android:progressDrawable="@drawable/peakbar" >            
        </ProgressBar>
        
        <ProgressBar
            android:id="@+id/progressBarPeakR"
            style="?android:attr/progressBarStyleHorizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="@dimen/activity_vertical_margin"
            android:max="32767"
            android:progress="0"
            android:progressDrawable="@drawable/peakbar">            
        </ProgressBar>    
        
        <SeekBar
            android:id="@+id/seekBarVolume"
            android:max="100"
            android:progress="50"
            android:layout_marginBottom="@dimen/activity_vertical_margin"
            android:thumb="@drawable/thumb"
            android:progressDrawable="@drawable/progress"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">               
           </SeekBar> 
        
       </LinearLayout>
       
    
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal|center_vertical"
        android:background="?android:attr/selectableItemBackground"
        android:gravity="center|bottom" >
        
        <Button
            android:id="@+id/buttonPlay"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:background="@drawable/buttons"
            android:text="@string/play"
            android:textColor="@color/darkersilver" >            
        </Button>

        <Button
            android:id="@+id/buttonPause"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:background="@drawable/buttons"
            android:text="@string/pause"
            android:textColor="@color/darkersilver" >            
        </Button>
        
        <Button
            android:id="@+id/buttonStop"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:background="@drawable/buttons"
            android:text="@string/stop"
            android:textColor="@color/darkersilver" >            
        </Button>        
    </LinearLayout>

</LinearLayout>

pgbPeakR = (ProgressBar)layout.findViewById(R.id.progressBarPeakR);
pgbPeakL = (ProgressBar)layout.findViewById(R.id.progressBarPeakL);
skbVolume = (SeekBar)layout.findViewById(R.id.seekBarVolume);
skbVolume.setOnSeekBarChangeListener(this);

03-20 20:09:33.032: E/AndroidRuntime(22923): FATAL EXCEPTION: main
03-20 20:09:33.032: E/AndroidRuntime(22923): java.lang.ClassCastException: android.widget.ProgressBar cannot be cast to android.widget.SeekBar
03-20 20:09:33.032: E/AndroidRuntime(22923):     at de.murdock.droidradio.MainFragment.onCreateView(MainFragment.java:107)
03-20 20:09:33.032: E/AndroidRuntime(22923):     at android.support.v4.app.Fragment.performCreateView(Fragment.java:1504)
03-20 20:09:33.032: E/AndroidRuntime(22923):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:942)