I used the sample code below for testing. I could not figure out what went wrong. Appreciate if you can point out what I need to do on setting up or using Reminder.
1) ShowParams.xaml is setup
2) Below is the code to add reminder:
Uri navigationUri = new Uri("/ShowParams.xaml" + queryString, UriKind.Relative);
            Reminder reminder = new Reminder(name);
            reminder.Title = titleTextBox.Text;
            reminder.Content = contentTextBox.Text;
            reminder.BeginTime = beginTime;
            reminder.ExpirationTime = expirationTime;
            reminder.RecurrenceType = recurrence;
            reminder.NavigationUri = navigationUri;
            // Register the reminder with the system.
            ScheduledActionService.Add(reminder);
Thanks