Android EditText doesn't show the Keyboard

I have a screen with three EditText's, and one of then, the first one, in the top of the screen doesn't call the keyboard when I click on it. I'm not using an AVD, I'm using my own device, and tested in others devices and same result. I'll put the screen here and the xml codes... there is nothing diferent between the EditTexts, just position. To make an input in that EditText I need to select one of the EditText above, and then the keyboard shows up. At least it doesn't hide when I select the first EditText again. I've already try the setFocus(true) and it doesn't solve my problem. please, help me! XML ``` <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:background="@drawable/background" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".SaldoCadastro" > <TextView android:id="@+id/tvTituloReg" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentTop="true" android:text="Saldo Banco" android:textAppearance="?android:attr/textAppearanceLarge" /> <TextView android:id="@+id/tvErroSenha1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/tvTituloReg" android:layout_marginTop="17dp" android:text="Insert on the field below how much you have in your bank." /> <TextView android:id="@+id/textView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/tvErroSenha1" android:layout_below="@+id/tvErroSenha1" android:layout_marginTop="41dp" android:text="Insert on the field below how much is your credit card limit." /> <EditText android:id="@+id/etSaldo" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/tvErroSenha1" android:ems="10" android:inputType="numberDecimal" > <requestFocus /> </EditText> <EditText android:id="@+id/etCartaoLimite" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/textView2" android:layout_below="@+id/textView2" android:ems="10" android:inputType="numberDecimal" /> <TextView android:id="@+id/textView3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/etCartaoLimite" android:layout_below="@+id/etCartaoLimite" android:text="About your credt card how much you&apos;ve spent already." /> <EditText android:id="@+id/etCartao" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/textView3" android:layout_below="@+id/textView3" android:ems="10" android:inputType="numberDecimal" /> <Button android:id="@+id/btRegisterSaldo" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/etCartao" android:layout_below="@+id/etCartao" android:layout_marginLeft="14dp" android:text="Register" /> ```