The latest version of managesieve plugin can not work with the embedded "lib / Net / Net_Sieve.php"
After refresh it to version 1.2.0 from pear.php.net - everything is OK

Error message is: "sieve[9369]: badlogin: ...... DIGEST-MD5 authentication failure"

IMAP server is: cyrus  - Cyrus timsieved v2.3.15
PHP version: PHP 5.2.11