I am trying to put in an ad but once the ad loads up, everything else in the program goes away leaving nothing but the ad.
Your linearlayouts height is set to fill_parent and that causes a problem since it's parent, your scrollview, is also set to height:fill_parent.
Try this:
<ScrollView android:id="@+id/scrollView1" android:layout_width="fill_parent" android:layout_height="fill_parent">
<LinearLayout android:id="@+id/linearLayout2" android:layout_width="fill_parent" android:layout_height="wrap_content">
<ImageView android:src="@drawable/item" android:layout_width="fill_parent" android:layout_gravity="center" android:layout_height="wrap_content" android:id="@+id/imageView1" android:scaleType="center"></ImageView>
</LinearLayout>
</ScrollView>
</LinearLayout>