I am having a similar problem:
WordPress database error: [Duplicate entry ‘0’ for key 1]
INSERT INTO wp_posts (ID, post_author, post_date, post_date_gmt, post_content, post_title, post_excerpt, post_status, comment_status, ping_status, post_password, post_name, to_ping, post_modified, post_modified_gmt, post_parent, menu_order) VALUES (”, ‘1’, ‘2006-01-03 10:18:19’, ‘2006-01-03 08:18:19’, ‘testing again’, ‘test’, ”, ‘publish’, ‘open’, ‘open’, ”, ‘test’, ”, ‘2006-01-03 10:18:19’, ‘2006-01-03 08:18:19’, ‘0’, ‘0’)
Warning: Cannot modify header information – headers already sent by (output started at /home/loginname/public_html/ibis/wp-includes/wp-db.php:98) in /home/loginname/public_html/ibis/wp-admin/post.php on line 170
The above solution doesn’t help- Can anyone help me?