Maybe when you don't focus the Item,TextColor is same as background color on current Theme .so you can't see them,just see the item text that you focus.
Solve : set different color against background_color.
you can use android.R.layout.simple_dropdown_item_1line and so on when you create Adapter ,or your own textViewResourceId like:
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:textSize="20dp"
android:gravity="center_vertical"
android:id="@android:id/text1"
android:paddingLeft="6.0dip"
android:paddingRight="6.0dip"
android:layout_width="fill_parent"
android:layout_height="50.0dip"
android:textColor="@android:color/black"
android:textColorHighlight="@android:color/black" />