How do I get Outlook to process an event update?

I am trying to create, update and delete an event in Outlook 2007 (but optimally it would work for all versions). Creating and deleting the event is working fine. I followed several threads but for some reason the update action failed.

When I double click on the ICS file, Outlook opens a window and the only choice I have is to delete. But the event it wants to delete is not the old one but the new one (even if it's not 开发者_如何学Gocreated yet). So when I click delete the old event remains here.

The UID is the same, sequence has been increase by 1, DTSTAMP in newer.

First event:

BEGIN:VCALENDAR
PRODID:-//Blatant Media Corporation//Absorb LMS//EN
VERSION:2.0
METHOD:PUBLISH
BEGIN:VEVENT
CLASS:PUBLIC
DTSTART;VALUE=DATE-TIME:20101111T13000000Z
DTEND;VALUE=DATE-TIME:20101111T14000000Z
UID:AbsorbClass150180
DESCRIPTION:A nov session for demoing only\n\nVenue:\nBoardroom 123\n\nInstructor:\nMike Owens\n\nCourse Description:\nInstructor Led Training (ILT) topic: First Aid\n\n------------------\nAbsorb Anywhere\nhttp://www.absorbtraining.com
LOCATION:Boardroom 123
SUMMARY:First Aid: Nov
DTSTAMP:20101107T15353400Z
LAST-MODIFIED:20101107T15353400Z
STATUS:CONFIRMED
SEQUENCE:0
END:VEVENT
END:VCALENDAR

Updated event:

BEGIN:VCALENDAR
PRODID:-//Blatant Media Corporation//Absorb LMS//EN
VERSION:2.0
METHOd:REQUEST
BEGIN:VEVENT
CLASS:PUBLIC
DTSTART;VALUE=DATE-TIME:20101111T15000000Z
DTEND;VALUE=DATE-TIME:20101111T16000000Z
UID:AbsorbClass150180
DESCRIPTION:A nov session for demoing only\n\nVenue:\nBoardroom 123\n\nInstructor:\nMike Owens\n\nCourse Description:\nInstructor Led Training (ILT) topic: First Aid\n\n------------------\nAbsorb Anywhere\nhttp://www.absorbtraining.com
LOCATION:Boardroom 123
SUMMARY:First Aid: Nov
DTSTAMP:20101108T15353400Z
LAST-MODIFIED:20101108T15353400Z
ORGANIZER:Owens
SEQUENCE:1
END:VEVENT
END:VCALENDAR

Add the following to both files:

ORGANIZER:donotreply@test.com

not sure why, but you can't seem to update events without this.