No puedo establecer imageLevel

I have ICS app with layout which use a ImageView with drawable list. I try to set imageLevel to it but pic doesn't change.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

<item
    android:maxLevel="0"
    android:drawable="@drawable/main_activity_idle" />

<item
    android:maxLevel="1"
    android:drawable="@drawable/main_activity_upload" />

<item
    android:maxLevel="2"
    android:drawable="@drawable/main_activity_download" />
</layer-list>


 <ImageView
    android:id="@+id/main_panel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingBottom="6dp"
    android:layout_below="@+id/main_panel_logo"
    android:layout_alignParentRight="true"
    android:src="@drawable/main__dr_list" />

statusIndicator = (ImageView) findViewById(R.id.main_panel_activity);
    statusIndicator.setImageLevel(0);

¿Sabes por qué sucede?