OK, i solved this issue for me with his script... Maybe this will help 
someone else:


#!/usr/bin/perl

use DBD::mysql;
use strict;

# CONFIGURE
my $user="$ARGV[0]";
my $database="$ARGV[1]";
my $host="localhost";
my $dbuser="root";
my $password=`gtc-crypt -a mysqlroot -p`;
chomp($password);

# Connect to the DB
my $dbh = 
DBI->connect("DBI:mysql:database=$database;host=$host","$dbuser", 
"$password", {'RaiseError' => 1}) || die "No connection to DB 
$database: $? $!";
$password="";

# Create synccalendar if not exists
# Get primary calendar of the user
my $sth = $dbh->prepare("SELECT share_name FROM kronolith_sharesng 
WHERE share_owner='$user'");
$sth->execute();
my $synccal;
my $nosynccal=1;
my $first=1;
while (my $cal = $sth->fetchrow_array()) {
  if ($first) {
   $synccal=$cal;
   $synccal=~s/^...../SYNC-/;
   $first=0;
  }
  else {
   if ($cal eq $synccal) {
    $nosynccal=0;
    last;
   }
  }
}
if (($nosynccal) && ($synccal)) {
  my $insert="INSERT INTO kronolith_sharesng (share_name, share_owner, 
share_flags, perm_creator_2, perm_creator_4, perm_creator_8, 
perm_creator_16, perm_creator_1024, perm_default_2, perm_default_4, 
perm_default_8, perm_default_16, perm_default_1024, perm_guest_2, 
perm_guest_4, perm_guest_8, perm_guest_16, perm_guest_1024, 
attribute_name, attribute_desc, attribute_color, share_parents) VALUES 
('$synccal', '$user', '0', '0', '0', '0', '0', '0', '0', '0', '0', 
'0', '0', '0', '0', '0', '0', '0', 'Sync', 'Only for syncing', 
'#ffffff', 'NULL')";
  $dbh->do($insert) || die "Error: $! $?";
}
exit 1 unless ($synccal);

# Get displayed calendars of user
my @cals;
my $sth = $dbh->prepare("SELECT pref_value FROM horde_prefs WHERE 
pref_scope='kronolith' AND pref_name='display_cals' AND 
pref_uid='$user'");
$sth->execute();
while (my $ref = $sth->fetchrow_hashref()) {
  my $cals= $ref->{'pref_value'};
  $cals=~s/^a:.+:{//;
  $cals=~s/i:.;s:23://g;
  $cals=~s/\"//g;
  $cals=~s/;}$//;
  @cals=split(/;/, $cals);
}
exit 1 unless ($cals[0]);

# Set Sync-Calendar in Horde-Prefs
$dbh->do("DELETE FROM horde_prefs WHERE pref_uid='$user' AND 
pref_name='sync_calendars' AND pref_scope='kronolith'");
$dbh->do("INSERT INTO horde_prefs (pref_uid, pref_scope, pref_name, 
pref_value) VALUES ('$user', 'kronolith', 'sync_calendars', 
'a:1:{i:0;s:23:\"$synccal\";}')");

# Clear the sync-calendar
$dbh->do("DELETE FROM kronolith_events WHERE calendar_id='$synccal'");

# Copy Calendars to sync-Calendar
foreach my $cal (@cals) {
  if ($cal eq $synccal) { next }
  my $sth = $dbh->prepare("SELECT * FROM kronolith_events WHERE 
calendar_id='$cal'");
  $sth->execute();
  while (my $ref = $sth->fetchrow_hashref()) {
   $ref->{'event_id'}=~s/^...../SYNC-/;
   my $insert="INSERT INTO kronolith_events (event_keywords, 
event_exceptions, event_recurinterval, event_recurdays, 
event_recurenddate, event_recurcount, event_baseid, 
event_exceptionoriginaldate, event_id, event_uid, event_creator_id, 
event_title, event_description, event_location, event_url, 
event_private, event_status, event_attendees, event_resources, 
event_modified, event_start, event_end, event_allday, event_alarm, 
event_alarm_methods, event_recurtype, calendar_id) VALUES 
('$ref->{'event_keywords'}', '$ref->{'event_exceptions'}', 
'$ref->{'event_recurinterval'}', '$ref->{'event_recurdays'}', 
'$ref->{'event_recurenddate'}', '$ref->{'event_recurcount'}', 
'$ref->{'event_baseid'}', '$ref->{'event_exceptionoriginaldate'}', 
'$ref->{'event_id'}', '$ref->{'event_uid'}', 
'$ref->{'event_creator_id'}', '$ref->{'event_title'}', 
'$ref->{'event_description'}', '$ref->{'event_location'}', 
'$ref->{'event_url'}', '$ref->{'event_private'}', 
'$ref->{'event_status'}', '$ref->{'event_attendees'}', 
'$ref->{'event_resources'}', '$ref->{'event_modified'}', 
'$ref->{'event_start'}', '$ref->{'event_end'}', 
'$ref->{'event_allday'}', '$ref->{'event_alarm'}', 
'$ref->{'event_alarm_methods'}', '$ref->{'event_recurtype'}', 
'$synccal')";
   $dbh->do($insert) || die "Error: $! $?";
  }
  $sth->finish();

  # Copy Horde-Histories-Settings for synchronization
  $sth = $dbh->prepare("SELECT * FROM horde_histories");
  $sth->execute();
  while (my $ref = $sth->fetchrow_hashref()) {
   if ($ref->{'object_uid'} =~ /^kronolith\:$cal/) {
    $ref->{'object_uid'}=~s/^kronolith\:$cal/kronolith\:$synccal/;
    my $insert="INSERT INTO horde_histories (object_uid, 
history_action, history_ts, history_desc, history_who, history_extra) 
VALUES ('$ref->{'object_uid'}', '$ref->{'history_action'}', 
'$ref->{'history_ts'}', '$ref->{'history_desc'}', 
'$ref->{'history_who'}', '$ref->{'history_extra'}')";
    $dbh->do($insert) || die "Error: $! $?";
    next;
   }
   if ($ref->{'object_uid'} =~ /^kronolith\:$synccal/) {
    $dbh->do("DELETE FROM horde_histories WHERE 
history_id='$ref->{'history_id'}'");
   }
  }
  $sth->finish();
}

No. There are a number of issues with this. For your case,the most 
important is that there is no way to mark calendar entries readonly in 
activesync. Editing an event in a read only calendar would appear to 
work on the client,would fail to update server side which would cause 
the client to continuously attempt to sync this change. There is a 
thread on the dev list with more detailed discussion about this 
owner-only limitation.

Hi,
Thank you very much for this change.
It seems multiple calendarsynchronizations are only working for 
owner-owned calendars. We have some group calendars and most of our 
users wants to be able to sync the calendars they have read-access to.
So is it possible to add synchronaization for "not" owned calendars?

Implemented in 3.0.5

Thanks - that worked for me too :-)

Clicking on the little disk symbol on the right hand side of the text 
worked for me. I also get a 0 Byte file when I use the text link.

Could it be, that the tar.gz is broken? Everytime I try do download 
it, I only get a empty 0 Byte sized file.

Thanks for the hint!

I am using the first version of the patch with a kolab 2.2.2 server, 
and there, the modification to _kronolith_synchronize is required. If 
I remove it (the second version of the patch) and create a new event 
in a calender selected for synchronization that is NOT the default 
calendar, this event will be duplicated on the client during 
synchronization, probably because some of the settings in the imap 
backend of kolab do not get correctly updated. With the patch to 
_kronolith_synchronize, everything works as expected.

I attached a patch against the current FRAMEWORK_3 cvs branch.
The .tar.gz file contains three .diffs for the files config/prefs.php, 
lib/api.php and lib/prefs.php in kronolith.

I tested the code with a thunderbird/funambol client and a test server 
setup, for me all sorts of adding, deleting and modifying events work 
and are correctly synchronized.

Where are conflicts handled (i.e. if the same event is changed on both 
client and horde before synchronizing)? I am wondering whether there 
is a possibility to configure what happens in that case (like 
duplicate event, client is right, horde is right, select newer, etc.)...

I will try to provide a patch soon (within the next one or two weeks). 
Is it possible to replace kronolith 2.3 api.php with the current 
version, or do I have to upgrade kronolith? If an upgrade is required, 
is it enough to upgrade kronolith only or do I have to upgrade the 
complete horde setup?

I changed my mind: Actually, i did not modify _kronolith_replace() at 
all, so if there is a problem with UIDs not identifying an event 
uniquely, that problem would have existed before my modifications.

The patch doesn't apply to the latest version of api.php at all. Can 
you provide a patch against the latest api.php version?
http://cvs.horde.org/h/chora/co.php/kronolith/lib/api.php?r=1.126.2.65&p=1

This shouldn't happen actually, because we check for the existence of 
the UID when adding new events.

Thank you, now I understand the problem. I will try to solve it as 
soon as I find some time for it. Currently however I have no idea how 
to determine which calendar an event belongs to...

This returns an event by the UID, which uniquely identifies the event 
across *all* calendars - in other words, two calendars that have an 
entry for the same event would contain the same UID so you can't be 
sure which calendar the event belongs to when using that method.

Hello,

as far as I understood, the event returned by
$event = $kronolith_driver->getByUID($uid);
knows which calendar it belongs to, and hence no manual lookup is required.
For me, the patch works, and modified events appear in the correct 
calendar (and are not moved to the default calendar). As the 
synchronization framework only knows about the events returned by 
_kronolith_list, events from calendars not used for synchronization 
should not be modified.
I did not know what _kronolith_synchronize is used for, and in the 
turba/lib/api.php, the _turba_synchronize routine is modified in an 
analogous way - sorry, I  removed the modifications (they did not harm 
in my setup, however).

Best regards

The patch is attached to this bug...

I'd like test the patch. Can you upload it?. Thanks

It looks like one part is missing: finding the correct calendar out of 
sync_cals when updating an existing event in _kronolith_replace().
OTOH please remove the changes to _kronolith_synchronize(), this 
method is for Kolab.
Beside those two issues, it's a great patch.

I added capabilities to synchronize multiple calendars with kronolith, 
inspired by the turba code. For me the patch works well with my mobile 
as well as with a thunderbird/lightning/funambol client.

Regards
Heienr