This doesn't happen all the time but it is becoming more common. When you load my home page there is a long list of errors then the page starts and the site runs with no problems; it just looks bad. Here are the errors:
WordPress database error: [Duplicate key name 'group_idpos']
ALTER TABLE wp_redirection_items ADD INDEX group_idpos (group_id,position)
WordPress database error: [Duplicate key name 'group']
ALTER TABLE wp_redirection_items ADD INDEX group (group_id)
WordPress database error: [Duplicate key name 'group']
ALTER TABLE wp_redirection_logs ADD INDEX group (group_id)
WordPress database error: [Duplicate key name 'redirection_id']
ALTER TABLE wp_redirection_logs ADD INDEX redirection_id (redirection_id)
WordPress database error: [Duplicate key name 'created']
ALTER TABLE wp_redirection_logs ADD INDEX created (created)
WordPress database error: [Duplicate key name 'ip']
ALTER TABLE wp_redirection_logs ADD INDEX ip (ip)
WordPress database error: [Duplicate key name 'group_id']
ALTER TABLE wp_redirection_logs ADD INDEX group_id (group_id)
WordPress database error: [Duplicate key name 'module_id']
ALTER TABLE wp_redirection_logs ADD INDEX module_id (module_id)
WordPress database error: [Duplicate key name 'name']
ALTER TABLE wp_redirection_modules ADD INDEX name (name)
WordPress database error: [Duplicate key name 'type']
ALTER TABLE wp_redirection_modules ADD INDEX type (type)
Warning: Cannot modify header information - headers already sent by (output started at /home/wannabet/public_html/wp-includes/wp-db.php:952) in /home/wannabet/public_html/wp-content/plugins/wp-super-cache/wp-cache-phase2.php on line 79