Widget data lost at application startup

I created a widget for my application. Everything works fine, and all the data displayed in the widget is displayed correctly. But sometimes what happens when I launch some other application, such as a camera, and start shooting a video for several seconds, stopping the video and closing the camera, suddenly all the data displayed in my widget is lost and does not show anything in widgets. I do not know if a problem occurs before I launch the application in Android 2.3.3, but as I upgrade my phone to Android 4.0, this problem shows.

Lost data appears again when the widget is updated in accordance with the time interval I set. So my question is why this data loss occurs, this is what I should do in my code. Please help me solve this problem.

The code I used

Widget_app_provider.xml File

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
android:initialLayout="@layout/widget_layout"
android:minHeight="56dp"
android:minWidth="56dp"
android:updatePeriodMillis="2100000" />

WidgetLayout.xml File

<ImageView
    android:id="@+id/backgroundImage"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:contentDescription="@string/tracking_status_faq_imageview_text"
    android:scaleType="fitXY" />

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:gravity="center_horizontal|center_vertical" >

    <TextView
        android:id="@+id/txt_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#5f5f5f"
        android:textSize="14dp" >
    </TextView>
</LinearLayout>

Widget.java File

public class Widget extends AppWidgetProvider implements Utilities
{
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) 
{      
    // Read data from register before  updating the widget
    CycleManager.getSingletonObject().readHistoryDateFromFile(context);
    CycleManager.getSingletonObject().ComputeAverages();

    // To prevent any ANR timeouts, we perform the update in a service
    context.startService(new Intent(context, UpdateService.class));
}

public static class UpdateService extends Service 
{
    @Override
    public void onStart(Intent intent, int startId) 
    {
        // Build the widget update for today
        RemoteViews updateViews = getValueFromCycleManager(this);

        // Push update for this widget to the home screen
        ComponentName thisWidget = new ComponentName(this, Widget.class);
        AppWidgetManager manager = AppWidgetManager.getInstance(this);
        manager.updateAppWidget(thisWidget, updateViews);
    }

    @Override
    public IBinder onBind(Intent arg0){
        // TODO Auto-generated method stub
        return null;
    }
    public RemoteViews getValueFromCycleManager(Context context) 
    {
        RemoteViews remoteViews = null;
        remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout);

        Date currentDate = calInstance.getTime();

        // set No of days remaining for next cycle start to the widgets 
        Date dtStart = CycleManager.getSingletonObject().getStartDate();
        int iAvgCycleLength = CycleManager.getSingletonObject().getAvgCycleTime();

        calInstance.setTime(dtStart);
        calInstance.add(Calendar.DATE, iAvgCycleLength);            
        Date dtNextCycleDate = calInstance.getTime();   

        Long noOfDaysLeft = dtNextCycleDate.getTime()- currentDate.getTime();
        noOfDaysLeft = ((noOfDaysLeft / (1000 * 60 * 60)) + 1) / 24;

        remoteViews.setTextViewText(R.id.txt_date, Long.toString(noOfDaysLeft));        
    }
}
}