Hello.

My roundcube does not allow me to login into my mailbox.  It just writes:
" invalid request no data was saved "

I enabled all logging settings in main.inc.php
$rcmail_config['smtp_log'] = true;
$rcmail_config['log_logins'] = true;
$rcmail_config['log_session'] = true;
$rcmail_config['sql_debug'] = true;
$rcmail_config['imap_debug'] = true;

/srv/www/roundcube/logs/errors is empty.  In /srv/www/roundcube/logs/sql I see normal SQL activity:
[29-Oct-2013 17:41:27 +0400]: [1] SET NAMES 'utf8';
[29-Oct-2013 17:41:27 +0400]: [2] SELECT vars, ip, changed FROM session WHERE sess_id = 'l33jvtmv3hs5aep93aq5hruoarbineohlvcgrg42u6vg8kf0nsd1';
[29-Oct-2013 17:41:27 +0400]: [3] DELETE FROM session WHERE sess_id = 'l33jvtmv3hs5aep93aq5hruoarbineohlvcgrg42u6vg8kf0nsd1';
[29-Oct-2013 17:41:27 +0400]: [4] DELETE FROM session WHERE sess_id = 'l33jvtmv3hs5aep93aq5hruoarbineohlvcgrg42u6vg8kf0nsd1';
[29-Oct-2013 17:41:27 +0400]: [5] INSERT INTO session (sess_id, vars, ip, created, changed) VALUES ('l33jvtmv3hs5aep93aq5hruoarbineohlvcgrg42u6vg8kf0nsd1', 'bGFuZ3VhZ2V8czo1OiJydV9SVSI7dGVtcHxiOjE7c2tpbnxzOjU6ImxhcnJ5Ijs=', '172.20.20.216', '2013-10-29 17:41:27', '2013-10-29 17:41:27');

My Apache is able to successfully save sessions to /var/lib/php5/

Rouncube 0.9.3
PHP suhosin module is not installed.
PHP 5.3.17 (via mod_php)