Background images in checkbox don't work well

I'm fairly new to android, and I'm making an app with several checkbox. and I have a problem in the design. In some phones (like the Moto G or Sony Ericsson m2) works perfect, but small cell (like Xperia X8 or S Galaxy Mini) it looks bad. The words appear incomplete, I do not understand why? This is the basic code:

<ScrollView
        android:id="@+id/mainScrollView"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        android:scrollbarThumbVertical="@drawable/custom_scroll_style"
        android:fillViewport = "true"
        >


        <LinearLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/idSecundario"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            >

            <CheckBox
                android:id="@+id/actuarioAdm0"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:onClick="itemClicked"
                android:fontFamily="Arial"
                android:text="@string/ch_analisis_matematico_I"
                android:background="@drawable/amarillo"
                android:button="@drawable/check"
                android:enabled="true"
                />

...

I tried changing the size of the images but still does not work. Someone would know what can happen?

Screenshots:

It looks good (large cell)

It does not look good. The words appear incomplete

I'm testing. It seems it's relative with background images, but I tried to resize and still not working.

I'll be very grateful if someone can help me. (Sorry if my English is not well)