Calendar not displaying End Points for events

I am working in a project that requires a read-only calendar on a dialog. I have stripped back the calendar controls(removed Insert,Update,Delete), leaving only RetrieveDayEvents, and ReadEvent.

I am having trouble displaying the boundries of my event data. An event 2 days long will not display. An event 2 months long will display BUT I can not navigate to the start or end dates.

I get an ASSERT that seems to come from Calendar1300vc80D.dll

I am testing with the following code:

CXTPCalendarEventsPtr CCalendarSQLDataProvider::RetrieveDayEvents_TestData()
{
CXTPCalendarEventsPtr pEvents = new CXTPCalendarEvents();
CXTPCalendarEventPtr pEvent = this->CreateNewEvent();

COleDateTimeSpan datOneDay(1.0);

//this works
COleDateTime datStart(2010,5,20,0,0,0);
COleDateTime datEnd(2010,7,20,0,0,0);     

//this Fails
//COleDateTime datStart(COleDateTime::GetCurrentTime());
//COleDateTime datEnd = datStart + datOneDay;

ASSERT(datStart.GetStatus()== COleDateTime::valid);
ASSERT(datEnd.GetStatus()== COleDateTime::valid);

pEvent->SetStartTime(datStart);
pEvent->SetEndTime(datEnd);     
pEvent->SetSubject(_T("Test subject"));
pEvent->SetBody(_T("Test subject body"));
pEvent->SetAllDayEvent(TRUE);
pEvent->SetLocation(_T("Anywhere"));
pEvent->SetLabelID(1);
pEvent->SetEventID(1);
pEvents->Add(pEvent);
return pEvents;

}

any insight would be good. THANKS