Unable to sync Lotus Notes Calendar with easysync 4.26

When trying to sync the Lotus Notes 8.0.2 calendar with a mobile device (WM6.5) the synchronisation failed stating: CRLNTransCalBase::FindOriginalStartDate - Could not find original start date of an exception. Ignoring possibly remaining exceptions.

It seems there are recurring entries in my calendar without start date. These entries were deleted after I synchronised another mobile phone (Nokia) which automaticly created entries dating back to 1900. These entries were deleted manually. Leaving some entries sort of Orphan (a recurring entry without the original start date).

Is there a way to find out which entries are orphan? How can I delete entries without a startdate?

The debug log shows:

ERROR: CRLNTransCalBase::FindOriginalStartDate - Could not find original start date of an exception. Ignoring possibly remaining exceptions.

27:53 LNTransCal::GetRecurringRecord - WARNING: Could not find the original start date; skipping possible deleted exceptions.

27:53 Enter CRLNTransCalBase::IsDocRepeatExpn

27:53 CRLNTransCalBase::IsDocRepeatExpn - Version: ; Flags: ; ApptType: 2; RepeatUnit: MD; NoticeType:

27:53 Enter CRLNTransCalBase::GetAppointmentType

27:53 Exit CRLNTransCalBase::GetAppointmentType

27:53 Enter CRLNTransBase::CompareExceptionFields

27:53 Enter CRLNTransCalBase::FindOriginalStartDate

27:53 Enter CRLNTransBase::AdjustPatternForRepeatWeekends

27:53 Exit CRLNTransBase::AdjustPatternForRepeatWeekends