WinRT Background Task with Time Trigger Error

Question

I have defined my Background Task as follows:

public sealed class BackgroundSynchronization:IBackgroundTask
{
        public async void Run(IBackgroundTaskInstance taskInstance)
        {
            BackgroundTaskDeferral _deferral = taskInstance.GetDeferral();

            //code
            //Network Calls
            //Updating Local DB (SQLite)

            myRepository.Save(entity);   // Saves entity in SQLite Table, and Entity has a  Current DateTime field too.

            deferral.Complete();
        }
}

And Task Register class as

public static class BackgroundTaskRegister {

    public static  BackgroundTaskRegistration RegisterBackgroundTask(string taskEntryPoint,string taskName,IBackgroundTrigger trigger,IBackgroundCondition condition)
    {
        foreach (var cur in BackgroundTaskRegistration.AllTasks)
        {

            if (cur.Value.Name == taskName)
            {
                return (BackgroundTaskRegistration)(cur.Value);
            }
        }

        var builder = new BackgroundTaskBuilder();

        builder.Name = taskName;
        builder.TaskEntryPoint = taskEntryPoint;
        builder.SetTrigger(trigger);

        if (condition != null)
        {
            builder.AddCondition(condition);
        }

        BackgroundTaskRegistration task = builder.Register();

        return task;
    }

}

And I have registered the triiger in my app as

    TimeTrigger myTrigger = new TimeTrigger(15, false);
    await BackgroundExecutionManager.RequestAccessAsync();

    string entryPoint = "BackgroundTask.BackgroundSynchronization";
    string taskName = "Example per 15 minute background task";
    BackgroundTaskRegistration tsk = BackgroundTaskRegister.RegisterBackgroundTask(entryPoint, taskName, myTrigger, null);

    tsk.Completed += new BackgroundTaskCompletedEventHandler(OnCompleted);

I also have OnComplete method in my App

 private async void OnCompleted(IBackgroundTaskRegistration task, BackgroundTaskCompletedEventArgs args)
 {
            var settings = ApplicationData.Current.LocalSettings;
            var message = settings.Values["backgroundSyncStatus"].ToString();
            var folder = ApplicationData.Current.LocalFolder;
            StorageFile file;
            var x = await File.DoesFileExistInLocalAsync("BackgroundTaskSucceedLog.txt");

            if (!x)
                file = await folder.CreateFileAsync("BackgroundTaskSucceedLog.txt");
            else
               file = await ApplicationData.Current.LocalFolder.GetFileAsync("BackgroundTaskSucceedLog.txt");

            await Windows.Storage.FileIO.AppendTextAsync(file, message.ToString() + " " + DateTime.Now.ToString() + Environment.NewLine);
 }

The background tasks triggers successfully, & the data is saved to SQLite DB myRepository.Save(entity); table only for the first run. I came to this conclusion as I had logged the entries in OnComplete method.

The logger results confused me more

Logger results

2/16/2015 10:51:41 PM     <--Data Saved in SQLite for this entry
2/16/2015 11:07:03 PM
2/16/2015 11:22:26 PM
2/16/2015 11:37:39 PM
2/16/2015 11:52:51 PM
2/17/2015 5:33:00 AM       <--Data Saved in SQLite for this entry

The data in SQLite is saved only for the first Background Task "for a day". I tried to Debug Background Task., For first run, Everything runs smoothly, & for subsequent run, the compiler after reaching myRepository.Save(entity);, jumps directly to OnComplete method. WHY.???