Version:            (using KDE KDE 3.5.2)
Installed from:    Debian testing/unstable Packages
OS:                Linux

An event is created in a "Calendar in Local Directory" resource using the following .ics file:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:Graham Cobb's OWA sync V0.4
BEGIN:VEVENT
CATEGORIES:X-OWA
DTSTART:20060531T160000Z
DTEND:20060531T170000Z
SUMMARY:GRC Test event
LOCATION:pin 3901
STATUS:CONFIRMED
DESCRIPTION:Objective:\nProvide overview of EMEA userconference to product marketing and operations to inform you of current plan and agenda and   obtain input.\nAgenda\nOverview of Event\nReview Agenda\nQuestions / Input\n
UID:grc-123
X-GRC-TESTING:Objective:\nProvide overview of EMEA userconference to product marketing and operations to inform you of current plan and agenda and   obtain input.\nAgenda\nOverview of Event\nReview Agenda\nQuestions / Input\n
END:VEVENT
END:VCALENDAR

(Note that both the DESCRIPTION and the X-GRC-TESTING attributes contain newlines, quoted as required for iCal format)

The event loads correctly and works correctly.  However, when it is exported to an iCalendar file, the following entry is written:

BEGIN:VEVENT
DTSTAMP:20060620T225904Z
ORGANIZER:MAILTO:
X-GRC-TESTING:Objective:
Provide overview of EMEA userconference to 
 product marketing and operations to inform you of current plan and agenda 
 and   obtain input.
Agenda
Overview of Event
Review Agenda
Questions / 
 Input

CREATED:20060620T223019Z
UID:grc-123
SEQUENCE:0
LAST-MODIFIED:20060620T223019Z
DESCRIPTION:Objective:\nProvide overview of EMEA userconference to 
 product marketing and operations to inform you of current plan and agenda 
 and   obtain input.\nAgenda\nOverview of Event\nReview Agenda\nQuestions 
 / Input\n
SUMMARY:GRC Test event
LOCATION:pin 3901
STATUS:CONFIRMED
CLASS:PUBLIC
PRIORITY:5
CATEGORIES:X-OWA
DTSTART:20060531T160000Z
DTEND:20060531T170000Z
TRANSP:OPAQUE
END:VEVENT

Note that the DESCRIPTION line is correctly quoted but the X-GRC-TESTING line is not.

This problem also occurs when using the KCal::ICalFormat toString method.

This problem causes the kdepim plug-in for Opensync to fail to synchronise any events containing unknown attributes with newlines and produce lots of error messages instead!