[Dovecot] Strange behavior on with "listescape" and "lda_mailbox_autocreate" - double entries

[Patrick De Zordo]

Hello Guys,
we are using Dovecot since years; all working flawless but one strange 
behavior:

Let me explain..

- we have enabled the "listescape" plugin in "15-lda.conf", 
"10-mail.conf" and "20-imap.conf".
- we use the following default namespace in "10-mail.conf":
--------------- 10-mail.conf -----------------------------------------
namespace {
   type = private
   prefix =
   separator = /
   inbox = yes
   subscriptions = yes
}
----------------------------------------------------------------------------------------

- we use a sieve script that automatically generates folders in the 
following form (example):
----------------------------------------------------------------------------------------
".INBOX.2014.05.patrick.incoming" for user "patrick at xx.com"
".INBOX.2014.05.patrick.outgoing" for user "patrick at xx.com"
".INBOX.2014.05.p\2edezordo.incoming" for user "p.dezordo at xx.com"
----------------------------------------------------------------------------------------

This is ok, but the automatically generated "subscriptions"-file of the 
user contains double lines (the second line is something strange?!);
the second one should not be created, its totally wrong..!

--------------- subscriptions -----------------------------------------
Trash
Sent
INBOX.2014.05.patrick.incoming
INBOX.2014.05.patrick.outgoing
INBOX.2014.05.p\2edezordo.incoming
INBOX\2e2014\2e05\2ep\5c2edezordo\2eincoming <----- this line!?!?!?
----------------------------------------------------------------------------------------

Have you any ideas whats going on?
Could this be a bug, or misconfiguration?

Thanks in advance!!

Greeting from Italy!
Patrick.