[Dovecot] %d does not expand to domain

[Giuliano Gavazzi]

Hello, dovecot-1.1.7 on FreeBSD 7.1.
Usernames have dot in them (like uname.example for a user in  
example.com).

in dovecot.conf I have:

   mail_location: maildir:/userhomes/maildirs/%d/%n/Maildir

and for authentication:

   username_format: %Ln

In the client, tried with CONE and Mail.app, I put the username as:

uname.example at example.com

So, the authentication works fine, as it extracts the uname.example  
from the uname.example at example.com supplied.

The mail_location does not:

Apr 27 17:21:26 drum dovecot: imap-login: Login: user=<uname.example>,  
method=PLAIN, rip=88.149.183.86, lip=88.149.202.106, TLS
Apr 27 17:21:26 drum dovecot: IMAP(name.example): Effective uid=1301,  
gid=1301, userhomes=/userhomes/example.com/uname
Apr 27 17:21:26 drum dovecot: IMAP(uname.example): Namespace:  
type=private, prefix=INBOX., sep=., inbox=yes, hidden=no, list=yes,  
subscriptions=yes
Apr 27 17:21:26 drum dovecot: IMAP(uname.example): maildir: data=/ 
userhomes/maildirs//uname.example/Maildir
Apr 27 17:21:26 drum dovecot: IMAP(uname.example): maildir++: root=/ 
userhomes/maildirs//uname.example/Maildir, index=, control=, inbox=/ 
userhomes/maildirs//uname.example/Maildir

it looks like the %d expands to the empty string.

Could this be due to the "." in the username?

Thanks

Giuliano