ListPreference is throwing a strange null pointer exception

I have an app that obtains a list of available Calendars and displays them in the Spinner.

I have checks to ensure that if the available Calendar list is empty, then ListPreference will still display "None available" in the Spinner.

I am using the ListPreference to display the Spinner in the Preferences tab.

Here is the preferences.xml:

<ListPreference android:title="Calendar"
android:key="calendars"
android:summary="Calendars to use for saving Appts"
android:selectable="true"
android:entryValues="@array/cal_entryvalues_list_preference"
android:entries="@array/cal_entries_list_preference"
android:defaultValue="0"
android:enabled="true"></ListPreference>

My users have reported the following error:

java.lang.NullPointerException at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java: 355) at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323) at android.widget.AbsListView.obtainView(AbsListView.java:1294) at android.widget.ListView.measureHeightOfChildren(ListView.java:1198) at android.widget.ListView.onMeasure(ListView.java:1109) at android.view.View.measure(View.java:8171) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3132) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java: 1012) at android.widget.LinearLayout.measureVertical(LinearLayout.java:381) at android.widget.LinearLayout.onMeasure(LinearLayout.java:304) at android.view.View.measure(View.java:8171) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3132) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java: 1012) at android.widget.LinearLayout.measureVertical(LinearLayout.java:381) at android.widget.LinearLayout.onMeasure(LinearLayout.java:304) at com.android.internal.widget.WeightedLinearLayout.onMeasure(WeightedLinearLayout.java: 60) at android.view.View.measure(View.java:8171) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3132) at android.widget.FrameLayout.onMeasure(FrameLayout.java:245) at android.view.View.measure(View.java:8171) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3132) at android.widget.FrameLayout.onMeasure(FrameLayout.java:245) at android.view.View.measure(View.java:8171) at android.view.ViewRoot.performTraversals(ViewRoot.java:801) at android.view.ViewRoot.handleMessage(ViewRoot.java:1727) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:123) at android.app.ActivityThread.main(ActivityThread.java:4627) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:521) at com.android.internal.os.ZygoteInit $MethodAndArgsCaller.run(ZygoteInit.java:868) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) at dalvik.system.NativeStart.main(Native Method)

The stack trace seems to be pointed all internal workings of Android. 开发者_如何转开发There is no reference to any of my code. This is happening on Android 2.1 as well as Android 2.2 platforms.

Unfortunately, I have not been able to reproduce the error on my Moto Droid. It appears from Developer Console logs that this is specific to certain phones (e.g: HTC Incredible).

Any idea what is going on here?