[Solved] Calendar event not being updated

ChangeEvent returns FALSE in bTest (see code below).. I've no idea because I only change the reminder minuts before start. I hope you can help me to solve the problem. Thanks.

Platform: Windows XP (32bit) - SP 3
Product: Xtreme Calendar Pro 2007 Vol 2 (MFC) (11.2.2)
Language: C++/MFC-8.0

XXXXX::XXXXX()
{
m_Sink.Advise(m_wndCalendar.GetConnection(), XTP_NC_CALENDAR_ON_REMINDERS, &CCalendar::OnReminders);
}

void XXXXX::OnReminders(XTP_NOTIFY_CODE Event, WPARAM wParam , LPARAM lParam)
{
CXTPCalendarRemindersManager *calRemindersManager = m_wndCalendar.GetRemindersManager();
CXTPCalendarReminders calRemindersL;
CXTPCalendarReminder *pcalReminder;
CXTPCalendarEventPtr cEvent;

calRemindersManager->GetActiveReminders(calRemindersL);

for (int i = 0; i < calRemindersL.GetCount(); i++)
{
    pcalReminder = calRemindersL.GetAt(i);
    cEvent = pcalReminder->GetEvent();

    //discard old events
    if (cEvent->GetEndTime() < COleDateTime::GetCurrentTime())
    {
      pcalReminder->Dismiss();
      continue;
    }

    if (cEvent->GetReminderMinutesBeforeStart() == 1)
    {
      cEvent->SetReminderMinutesBeforeStart(0);
      BOOL bTest = m_wndCalendar.GetDataProvider()->ChangeEvent(cEvent);
    }
    pcalReminder->Dismiss();
}
}


Events were created with SetReminderMinutsBeforeStart(1).

[Solved]
In all test cases the event I was trying to modify was modifing the recurrence pattern instead of the Ocurrence.