I upgraded libical to 1.0 from 0.48 and Korganizer shows no events in my calendar.

My ~/.xsession-errors is full of messages like these:

plasma-desktop(415)/akonadiserializer (calendar) Akonadi::SerializerPluginKCalCore::deserialize: Failed to parse incidence! Item id =  135277 Storage collection id  7 parentCollectionId =  7 
plasma-desktop(415)/akonadiserializer (calendar) Akonadi::SerializerPluginKCalCore::deserialize: "BEGIN:VCALENDAR
PRODID:-//K Desktop Environment//NONSGML libkcal 3.2//EN
VERSION:2.0
BEGIN:VTODO
DTSTAMP:20130507T153453Z
CREATED:20130507T153453Z
UID:182254e5-3f1a-42dd-b4dc-3e9fa9a54de2
LAST-MODIFIED:20130507T153453Z
SUMMARY:Portare foto in segreteria
CATEGORIES:UniBA
PERCENT-COMPLETE:0
END:VTODO

END:VCALENDAR" 
plasma-desktop(415)/libakonadi Akonadi::ItemSerializer::deserialize: Unable to deserialize payload part: "RFC822" 
plasma-desktop(415)/libakonadi Akonadi::ItemSerializer::deserialize: Payload data was:  "BEGIN:VCALENDAR
PRODID:-//K Desktop Environment//NONSGML libkcal 3.2//EN
VERSION:2.0
BEGIN:VTODO
DTSTAMP:20130507T153453Z
CREATED:20130507T153453Z
UID:182254e5-3f1a-42dd-b4dc-3e9fa9a54de2
LAST-MODIFIED:20130507T153453Z
SUMMARY:Portare foto in segreteria
CATEGORIES:UniBA
PERCENT-COMPLETE:0
END:VTODO

END:VCALENDAR" 

Reproducible: Always

Steps to Reproduce:
1. Upgrade libical to 1.0
2. Restart akonadi
3. See ~/.xsession-errors
Actual Results:  
Akonadi fails to parse incidence

Expected Results:  
Akonadi parse the events correctly.

KDE 4.10.3
libical 1.0