[Dovecot] managesieve und virtual plugin error v2.0

[Oliver Eales]

Hello,
i have a problem with the managesieve plugin and a virtual namespace in 
v2.0.
The managesieve plugin complains about an unknown storage driver virtual 
when i try to log intot the managesieve. I don't know if this is quite a 
recent  problem or if it exists  for a while, as i configured the 
virtual namspace from scratch. (The virtual namespace itself is working.)

Jun 28 13:55:54 managesieve-login: Info: Login: user=<1000000000032>, 
method=PLAIN, rip=::1, lip=::1, mpid=30947, secured
Jun 28 13:55:54 managesieve: Debug: Added userdb setting: 
plugin/quota_rule=*:storage=1073741824B
Jun 28 13:55:54 managesieve(1000000000032): Debug: Effective uid=20001, 
gid=20001, home=/mail/001/32/00/00/1000000000032
Jun 28 13:55:54 managesieve(1000000000032): Debug: Namespace 
type=private: type=private, prefix=, sep=., inbox=yes, hidden=no, list=ye
s, subscriptions=yes
Jun 28 13:55:54 managesieve(1000000000032): Debug: fs: 
root=/mail/001/32/00/00/1000000000032-dbox, 
index=/mail/001/32/00/00/1000000000
032-dbox/index, control=, inbox=
Jun 28 13:55:54 managesieve(1000000000032): Debug: Namespace : 
type=private, prefix=virtual., sep=., inbox=no, hidden=no, list=yes, su
bscriptions=yes
Jun 28 13:55:54 managesieve(1000000000032): Error: user 1000000000032: 
Initialization failed: Namespace 'virtual.': Unknown mail stora
ge driver virtual
Jun 28 13:55:54 managesieve(1000000000032): Error: Invalid user 
settings. Refer to server log for more information.

I am using dovecot-2.0-pigeonhole 1301:1def8519d775 and dovecot-2.0 
11638:5326d6b2f36e

excerpt from confs:
protocols = imap pop3 lmtp sieve
mail_location =  dbox:%h-dbox:INDEX=%h-dbox/index
namespace type=private {
   separator = .
   prefix =
   inbox = yes
}
namespace {
   prefix = virtual.
   separator = .
   location = virtual:%h-dbox/virtual:INDEX=%h-dbox/index/virtual
}
service managesieve-login {
   inet_listener  managesieve {
   }
}

Regards,
Oliver Eales