[imp] Error when comminicating with server and no imap folders

[Илья]

Hi! I'm using imp 6.1.4 with horde portal 5.1.4. On main page of imp I'm 
getting "Error when comminicating with server", and my folders are not 
displaying.
In horde.log nothing suspicious but:
2013-09-06T10:17:15+00:00 DEBUG: HORDE [imp] Load config file (conf.php; 
app: imp) [pid 20816 on line 409 of "/usr/share/pear/Horde.php"]
2013-09-06T10:17:15+00:00 DEBUG: HORDE [horde] RequestConfiguration in 
Horde_Controller_Runner: Horde_Core_Controller_RequestConfiguration Object
(
     [_classNames:protected] => Array
         (
             [controller] => Horde_Core_Controller_NotFound
             [settings] => Horde_Controller_SettingsExporter_Default
         )

     [_application:protected] => services
)
My setup: Nginx 1.4.2+php-fpm+php 5.4.19+dovecot 2. Connection to Imap 
server seems to be ok.
Regards, Ilya.