The latest Thunderbird Lightning plugin does not care much for that file. The ics output from Lightning also looks noticeably different.
~Bradley
Christopher A. Bier wrote:
The file follows the iCalendar standard published at: http://tools.ietf.org/html/rfc2445
phpiCalendar and Sunbird don't seem to have any problems with it, which might indicate a problem with google and Konqueror. If you find out what the error is, I'll be happy to modify the calendar.