marginTop and marginBottom don't work for LinearLayout

Main(container) LinearLayout:

<LinearLayout
    android:id="@+id/LinearHome"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
</LinearLayout>

Child LinearLayouts (I'm adding them dynamically by inflating new one):

<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/lnote"
    android:layout_marginTop="10dp"
    android:layout_marginBottom="10dp" />

What's the problem?