Problem is solved.
I compare WP 2.33 ver. and 2.6 ver. wp_comments database table and note that no diferences…
But after that I look at fresh 2.6 wp_comments table and see diferences.
Here i will put wordpress 2.6 table (without comments)
WordPress 2.6
-- phpMyAdmin SQL Dump
-- version 2.11.6
-- https://www.phpmyadmin.net
--
-- Host: localhost
-- Generation Time: Aug 11, 2008 at 04:08 AM
-- Server version: 5.0.51
-- PHP Version: 5.2.6
SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO";
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES latin1 */;
--
-- Database: yourdatabase_name
--
-- --------------------------------------------------------
--
-- Table structure for table wp_comments
--
CREATE TABLE IF NOT EXISTS wp_comments (
comment_ID bigint(20) unsigned NOT NULL auto_increment,
comment_post_ID int(11) NOT NULL default '0',
comment_author tinytext NOT NULL,
comment_author_email varchar(100) NOT NULL default '',
comment_author_url varchar(200) NOT NULL default '',
comment_author_IP varchar(100) NOT NULL default '',
comment_date datetime NOT NULL default '0000-00-00 00:00:00',
comment_date_gmt datetime NOT NULL default '0000-00-00 00:00:00',
comment_content text NOT NULL,
comment_karma int(11) NOT NULL default '0',
comment_approved varchar(20) NOT NULL default '1',
comment_agent varchar(255) NOT NULL default '',
comment_type varchar(20) NOT NULL default '',
comment_parent bigint(20) NOT NULL default '0',
user_id bigint(20) NOT NULL default '0',
PRIMARY KEY (comment_ID),
KEY comment_approved (comment_approved),
KEY comment_post_ID (comment_post_ID),
KEY comment_approved_date_gmt (comment_approved,comment_date_gmt),
KEY comment_date_gmt (comment_date_gmt)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=282 ;
--
-- Dumping data for table wp_comments
--
Drop old wp_comments table in PHPMyAdmin area and import new changed data. All will work.