ImageButton from child layout onClick method not working

I have ImageButton on my View that is not working (method not called) when I try to click on it, but it is working if I click using the emulator keyboard. adb shell logcat doesn't print anything.

my main.xml layout:

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android">  
    <LinearLayout   
        android:id="@+id/btn"   
        android:orientation="vertical"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        >
        <ImageButton            
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:layout_gravity="center_horizontal"  
            android:src="@drawable/ic_btn"
            android:clickabl开发者_如何学运维e="true"
            android:onClick="click"         
         />
         <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:text="Text" />
    </LinearLayout>                   
</merge>

the click method in activity:

public void click(View view) {
    tv.setText("clicked");
}

And if I put the ImageButton as direct child element of <merge>, the click method is working. My build target is Android 2.2. So, what is wrong here?

UPDATE I just know that this is because I have animation on the button, and location of the button is not updated after animation end. I didn't include that previously because I didn't know if it is related.