Fantastic. Looking forward to it. Thanks!
Hi Alexander, thanks for looking into this. The only failure is in the direction from Horde server to Outlook 2010 (not in the other direction, and not to other clients), and only for tasks whose status is being updated to completed (not for tasks whose status is being updated to incomplete) . The information sent from Horde was provided in the attachment vcalendar.txt. I presume that's the vtodo. It shows status:completed but does not have a percentage completed. I hope this is what you were asking...
Task not updated as completed in Outlook 2010