Apps Multiple imageviews in a linear layout issue

[Eikon777]

I am using a linear layout to draw a scalable background in my app. I am then defining multiple imageviews inside the linear layout, all of which are PNGs containing a transparency layer. I am wanting to overlay these transparent imageviews on top of the background. My issue is that only the first defined imageview shows on top of the background, any subsequent imageviews do not appear.

CODE: Note that imgSen1 appears properly with transparency overlaid on the background. imgSen2 does not appear. If I define imgSen2 first, and imgSen1 second, imgSen2 then appears properly, as if only the first defined imageview can be seen. I would like to have multiple imageviews with transparency overlaying the background. Thanks for your help
[HIGH]
<LinearLayout
android:layout_width="627dp"
android:layout_height="436dp"
android:layout_centerInParent="true"
androidaddingTop="0dp"
androidaddingBottom="0dp"
androidaddingLeft="0dp"
androidaddingRight="0dp"
android:background="@drawable/back9"
androidrientation="vertical" >

<ImageView
android:id="@+id/imgSen1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_vertical|center_horizontal"
android:scaleType="fitXY"
android:contentDescription="@string/EMF_Title"
androidrientation="horizontal"
android:src="@drawable/sen1" />

<ImageView
android:id="@+id/imgSen2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_vertical|center_horizontal"
android:scaleType="fitXY"
android:contentDescription="@string/EMF_Title"
androidrientation="horizontal"
android:src="@drawable/sen2" />

</LinearLayout>
[/HIGH]

 

[out of ideas]

try layout_height:"wrap_content" instead of fill_parent