#8 Error on converting recurring events

[Ubbo]

The sync from a SyncML-compatible device doesn't work properly, I've lost all recurring events. Here is an example of vcalendar not copied to the caldav-server.

BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VTIMEZONE
TZID:Europe/Berlin
BEGIN:DAYLIGHT
DTSTART:20090329T020000
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:Europe/Berlin
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20091025T030000
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:Europe/Berlin
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:040000008200E00074C5B7101A82E0080000000040A45A704AE0C9010000000000000000100000009FD7225489C30146940F3E45C6CA3634
CLASS:PUBLIC
DTSTART;TZID=Europe/Berlin:20090531T080000
DTEND;TZID=Europe/Berlin:20090531T080000
PRIORITY:0
SEQUENCE:0
ORGANIZER:
LAST-MODIFIED:20100715T200803Z
RRULE;TZID=Europe/Berlin:FREQ=YEARLY;INTERVAL=1;BYMONTH=5;BYMONTHDAY=31;UNTIL=21000531T080000
X-FUNAMBOL-ALLDAY:0
DESCRIPTION:
SUMMARY:Friend's Birthday
LOCATION:
BEGIN:VALARM
TRIGGER;TZID=Europe/Berlin;VALUE=DATE-TIME:20090531T080000
REPEAT:0
END:VALARM
END:VEVENT
END:VCALENDAR