Apparently I too am having same or similar problems as delineated above. My issue comes into play when I click the "save and continue editing" or the "save" button in the "Write" section of the Admin Panel. The "Post" button works completely fine. Danny's suggestion above did ameliorate the problem.
My site is running with PHP 5, MySQL 5, and IIS 6. Here's the error I get:
WordPress database error: [Incorrect datetime value: '' for column 'post_date' at row 1]
INSERT INTO wp_posts (post_author, post_date, post_date_gmt, post_content, post_content_filtered, post_title, post_excerpt, post_status, comment_status, ping_status, post_password, post_name, to_ping, pinged, post_modified, post_modified_gmt, post_parent, menu_order, post_mime_type) VALUES ('1', '', '', 'Test', '', 'Test', '', 'draft', 'open', 'closed', '', '', '', '', '', '', '0', '0', '')
WordPress database error: [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 3]
SELECT category_id FROM wp_post2cat WHERE post_id =
WordPress database error: [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' 1)' at line 2]
INSERT INTO wp_post2cat (post_id, category_id) VALUES (, 1)
Warning: Cannot modify header information - headers already sent by (output started at E:Websitesinterstellar-travel.comwwwrootwp-includeswp-db.php:102) in E:Websitesinterstellar-travel.comwwwrootwp-adminpost.php on line 59
Hopefully the folks with get this version compatible with the latest version of MySQL.