Android update 4.4.2 is messing with my button margins

Question

I am currently developing a game for android tablets and, recently, I updated one of my tablets to android 4.4.2. My other tablet, on the other hand, remained without any updates (still in version 4.1.2). They have the same size and are the same model, but recently I realized that, in exactly one of the game screens(the others seem fine), my updated tablet positions a button with a different marginBottom. The button is inside a relativeLayout, by the way. The unupdated tablet has the same button in a perfect margin(as displayed in the ADT). What's going on and how do I solve it? These tablets are identical, except for the update!

EDIT: screenshots

EDIT : here's the code of my XML(the button I'm talking about is the one with the android:id=confirmar_escolha_categorias):

 <!-- TELA DE ESCOLHA UMA CATEGORIA -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/tela_escolha_categoria"
tools:context="br.ufrn.dimap.pairg.sumosensei.EscolhaNivelActivity$PlaceholderFragment"
android:background="@drawable/background_login_sumo_sensei_opaco" >


<ImageView
    android:id="@+id/fundo_escolhaCategorias"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/flamula_casual"
    android:layout_marginTop="-20dp"
    android:layout_centerHorizontal="true"
    android:layout_below="@+id/teto_flamula_casual_criar_sala" />

<RelativeLayout
    android:id="@+id/id_componentes_filtrar_categoria_criar_sala"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/fundo_escolhaCategorias"
    android:layout_alignLeft="@id/fundo_escolhaCategorias"
    android:layout_alignRight="@id/fundo_escolhaCategorias"
    android:layout_alignTop="@id/fundo_escolhaCategorias"
    android:visibility="visible" >

<LinearLayout
    android:id="@+id/ambas_as_listas"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="20dp"
    android:layout_below="@+id/textoTituloEscolhaCategorias"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentBottom="true"
    android:weightSum="1" >

<ListView
    android:id="@+id/listaCategoriasPesquisaSalas1"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="0.5"
    android:layout_marginTop="20sp"
    android:layout_marginLeft="20dp"
    android:layout_marginRight="5dp"
    android:divider="@android:color/transparent"
    android:dividerHeight="35dp"
    android:listSelector="@android:color/transparent" 
    android:cacheColorHint="@android:color/transparent"
    android:adjustViewBounds="true" >
</ListView>

<ListView
    android:id="@+id/listaCategoriasPesquisaSalas2"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="0.5"
    android:layout_marginTop="20sp"
    android:layout_marginRight="20sp"
    android:layout_marginLeft="5dp"
    android:divider="@android:color/transparent"
    android:dividerHeight="35dp"
    android:listSelector="@android:color/transparent" 
    android:cacheColorHint="@android:color/transparent"
    android:adjustViewBounds="true">
</ListView>
</LinearLayout>

<TextView
    android:id="@+id/textoTituloEscolhaCategorias"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"
    android:gravity="center"
    android:layout_marginTop="50dp"
    android:layout_marginBottom="10dp"
    android:text="@string/escolha_categoria"
    android:textSize="40sp"
    android:textColor="#ffffff"
    android:textAppearance="?android:attr/textAppearanceMedium" />

<RelativeLayout android:id="@+id/relativePraCEntralizarBotao"
     android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="70dp">


<Button
    android:id="@+id/confirmar_escolha_categorias"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:background="@drawable/botao_ok_filtragem"
    android:text="@string/botao_escolher_categorias"
    android:textColor="#FFFFFF"
    android:textSize="25sp"
    android:layout_marginRight="70dp"
    android:layout_marginBottom="90dp"/>



    </RelativeLayout>
</RelativeLayout>



<ImageView
    android:id="@+id/teto_flamula_casual_criar_sala"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:src="@drawable/parte_cima_flamula_casual" />

<ImageView
    android:id="@+id/fitaVermelha_criar_sala"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/fundo_escolhaCategorias"
    android:layout_below="@+id/fundo_escolhaCategorias"
    android:layout_marginTop="-20dp"
    android:src="@drawable/parte_baixo_flamula_casual_vermelho" />
<ImageView
    android:id="@+id/fitaVerde_criar_sala"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="-5dp"
    android:layout_alignRight="@+id/fundo_escolhaCategorias"
    android:layout_below="@+id/fundo_escolhaCategorias"
    android:src="@drawable/parte_baixo_flamula_casual_verde" />