Don’t bother using wpdb to update post content, use wp_update_post instead!
http://codex.wordpress.org/Function_Reference/wp_update_post
Instead of
$wpdb->update($seo_tblPosts, array('post_content'=>$seo_pageContents), array('ID'=>$row_id));
Do:
// Update post 37
$my_post = array();
$my_post['ID'] = $row_id;
$my_post['post_content'] = $seo_pageContents;
// Update the post into the database
wp_update_post( $my_post );
As a side benefit it fires all the hooks so caching works as it should, RSS feeds get refreshed, etc
There’s very, very few reasons to manipulate the post table using wpdb. There are many, many good reasons and advantages to using the WP Core post editing functions instead.
And as always, practice safe data handling by validating sanitizing and escaping your data, else automated programs may test your site and find horrible horrible security holes and break everything horribly.