Using a ScrollView with three LinearLayouts inside

I got a problem with an .xml file of an Android project. Particularly, I need to have a Scroll View for the major part of the screen a footer underneath. The ScrollView is the parent of a LinearLayout which keeps three LinearLayouts inside. The first twos LinearLayout are correctly shown, but the third has never been shown.

I don't understand the reason why it happens: if I put the third LinearLayout in first position, everyone is correctly showed.

This is my code:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://ift.tt/nIICcg"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fillViewport="true"
    android:orientation="vertical" >

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                >

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="AppInfo"
                    android:padding="5dp"
                    android:id="@+id/bread" />

                <HorizontalScrollView
                    android:id="@+id/horizontal_scroll"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:fillViewport="true">

                    <LinearLayout
                        android:id="@+id/layout_image_container"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:orientation="horizontal"
                        >

                    </LinearLayout>

                </HorizontalScrollView>

            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:background="#ffffffff"
                android:gravity="fill_horizontal"
                android:layout_gravity="top"
                android:id="@+id/attivita_linear"
                android:padding="10dp"
                android:isScrollContainer="true">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Nome Attività"
                    android:id="@+id/textView_nome"
                    android:layout_gravity="center_vertical|center_horizontal"
                    android:textSize="30dp"
                    android:paddingBottom="35dp" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Indirizzo:  "
                    android:id="@+id/textView_indirizzo"
                    android:textSize="20dp"
                    android:textIsSelectable="false"
                    android:paddingBottom="5dp" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Telefono:  "
                    android:id="@+id/textView_tel"
                    android:textSize="20dp"
                    android:textIsSelectable="false"
                    android:paddingBottom="5dp" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Email:  "
                    android:id="@+id/textView_email"
                    android:textSize="20dp"
                    android:textIsSelectable="false"
                    android:paddingBottom="5dp" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="www:  "
                    android:id="@+id/textView_www"
                    android:textSize="20dp"
                    android:textIsSelectable="false" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Descrizione:  "
                    android:id="@+id/textView_descrizione"
                    android:textSize="20dp"
                    android:textIsSelectable="false" />

            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal"
                android:background="#000000"
                android:gravity="fill_horizontal"
                android:layout_gravity="top"
                android:id="@+id/attivita_buttons"
                android:padding="10dp"
                android:isScrollContainer="true">

                <ImageButton
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:src="@drawable/ic_action_call"
                    android:background="@drawable/ic_action_call"
                    android:contentDescription="prova" />

                <ImageButton
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:src="@drawable/ic_action_call"
                    />

                <ImageButton
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:src="@drawable/ic_action_call"
                    />

            </LinearLayout>

        </LinearLayout>

    </ScrollView>

    <RelativeLayout
        android:id="@+id/footer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:background="@drawable/cola">
        </FrameLayout>

    </RelativeLayout>

</RelativeLayout>

Hope you can help me.

Any answer would be appreciated.