2.2b2 distribution list problem

[rdeiriar at lascondes.cl]

I've just updated to 2.2 beta 2 and have noticed two problems so far,  
one easy to solve, one serious.

a) The easy one is the missing tmp directory in

/kolab/var/kolab/www/horde/

Required in order to be able to send attachments from Horde's webmail

b) The difficult one is the failure of the distribution lists problem.

An email sent to a list is received three times, then a 550 error is  
returned to the sender.

The error message reads:

------------------------------------------------------------

This is the mail system at host correo.xxxx.cl.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                    The mail system

<lista1 at xxxx.cl>: service unavailable. Command output: Failed to set
     recipient: Mailbox unknown.  Either there is no mailbox associated with
     this name or you do not have authorization to see it. 5.1.1 User unknown,
     code 550

Where lista1 at xxxx.cl is the list name.

The relevant part of postfix's log reads.

-------------------------------------------------------------

Nov 12 12:44:05 correo.xxxx.cl <info> postfix/pipe[94964]:  
397ADDE745C: to=<lista1 at xxxx.cl>, relay=kolabfilter, delay=0.31,  
delays=0.01/0/0/0.3, dsn=2.0.0, status=sent (delivered via kolabfilter  
service)
Nov 12 12:44:05 correo.xxxx.cl <info> postfix/pipe[94964]:  
397ADDE745C: to=<mponce at xxxx.cl>, orig_to=<lista1 at xxxx.cl>,  
relay=kolabfilter, delay=0.31, delays=0.01/0/0/0.3, dsn=2.0.0,  
status=sent (delivered via kolabfilter service)
Nov 12 12:44:05 correo.xxxx.cl <info> postfix/pipe[94964]:  
397ADDE745C: to=<rdeiriar at xxxx.cl>, orig_to=<lista1 at xxxx.cl>,  
relay=kolabfilter, delay=0.31, delays=0.01/0/0/0.3, dsn=2.0.0,  
status=sent (delivered via kolabfilter service)
Nov 12 12:44:05 correo.xxxx.cl <info> postfix/smtp[94548]:  
44407DE745F: to=<lista1 at xxxx.cl>, relay=127.0.0.1[127.0.0.1]:10024,  
delay=0.44, delays=0.12/0/0.01/0.32, dsn=2.0.0, status=sent (250 2.0.0  
Ok: queued as A63C4DE745D)
Nov 12 12:44:05 correo.xxxx.cl <info> postfix/smtp[94548]:  
44407DE745F: to=<mponce at xxxx.cl>, orig_to=<lista1 at xxxx.cl>,  
relay=127.0.0.1[127.0.0.1]:10024, delay=0.44, delays=0.12/0/0.01/0.32,  
dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as A63C4DE745D)
Nov 12 12:44:05 correo.xxxx.cl <info> postfix/smtp[94548]:  
44407DE745F: to=<rdeiriar at xxxx.cl>, orig_to=<lista1 at xxxx.cl>,  
relay=127.0.0.1[127.0.0.1]:10024, delay=0.44, delays=0.12/0/0.01/0.32,  
dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as A63C4DE745D)
Nov 12 12:44:06 correo.xxxx.cl <info> postfix/pipe[94565]:  
A63C4DE745D: to=<lista1 at xxxx.cl>, relay=kolabmailboxfilter,  
delay=0.34, delays=0.02/0.01/0/0.32, dsn=5.3.0, status=bounced  
(service unavailable. Command output: Failed to set recipient: Mailbox  
unknown.  Either there is no mailbox associated with this name or you  
do not have authorization to see it. 5.1.1 User unknown, code 550 )
Nov 12 12:44:06 correo.xxxx.cl <info> postfix/pipe[94567]:  
A63C4DE745D: to=<mponce at xxxx.cl>, orig_to=<lista1 at xxxx.cl>,  
relay=kolabmailboxfilter, delay=0.8, delays=0.02/0.01/0/0.78,  
dsn=2.0.0, status=sent (delivered via kolabmailboxfilter service)
Nov 12 12:44:06 correo.xxxx.cl <info> postfix/pipe[94559]:  
A63C4DE745D: to=<rdeiriar at xxxx.cl>, orig_to=<lista1 at xxxx.cl>,  
relay=kolabmailboxfilter, delay=1, delays=0.02/0.54/0/0.47, dsn=2.0.0,  
status=sent (delivered via kolabmailboxfilter service)

--------------------------------------------------------

Any ideas on where to look for a solution ?

Best regards,
Roberto