Hi Pierre,
Hope all is well. I got your log over at support and this looks like the culprit here:
Jun 12, 2012 6:21:56 PM com.prosc.webdav.WebDAV service
WARNING: Error handling PUT request for /zulu/calendars/ZuluSampleData/348e34f5-4fed-4543-a3ba-af68e00219b8/e638767b-13a7-4160-8fc1-bbe80ad09986.ics: com.prosc.webdav.ActionUnauthorizedException: com.prosc.fmpjdbc.FileMakerException: 201: "Field cannot be modified" - You cannot change the value of calculation fields or other fields where modification is prohibited. (JDBC URL: jdbc:fmp360://localhost/ZuluSampleData, SSL: false / SQL statement: UPDATE "om" SET "summary_zulu"=?, "zulu_ALARM_EMAIL_RECIPIENTS"=?, "zulu_ALARM_TYPE"=?, "zulu_ALARM_TRIGGER_MINUTES"=?, "note_zulu"=?, "data_fim"=?, "zulu_UUID"=?, "TimeStart"=?, "zulu_ICAL_DATA"=?, "data_inicio"=?, "zulu_LOCATION"=?, "zulu_ALARM_TRIGGER_TIMESTAMP"=?, "TimeEnd"=?, "zulu_URL"=?, "zulu_DELETED"=?, "c_zulu_filter_values"=?, "-script"=? WHERE "id"=? / SQL params: [g-sl erva doce granel-kg 1250kg RAHDA pp1474, null, null, null, pp1474 g-sl erva doce granel-kg 1250paepp588Reator 1250kgfeito:, com.prosc.fmpjdbc.DateWithZone@647e8969, e638767b-13a7-4160-8fc1-bbe80ad09986, com.prosc.fmpjdbc.TimeWithZone@2f6f800a
FileMaker Server is throwing a 201 error, which means one of the fields you have mapped for this calendar ( UUID:348e34f5-4fed-4543-a3ba-af68e00219b8/e638767b-13a7-4160-8fc1-bbe80ad09986 ) is not modifiable either because it's a calculation field or it's been set to not be modifiable in the field set-up. (maybe that c_zulu_filter_values?)
If you need a calculated value, you can use an auto-enter calculation, but all mapped zulu fields do need to modifiable.
Please let me know if that helps,
Jason