Error message

• Warning: Cannot modify header information - headers already sent by (output started at /data/sigrok.org/apache/blog/includes/common.inc:2780) in drupal_send_headers() (line 1486 of /data/sigrok.org/apache/blog/includes/bootstrap.inc).
• PDOException: SQLSTATE[HY000]: General error: 1033 Incorrect information in file: './blogdb/semaphore.frm': SELECT expire, value FROM {semaphore} WHERE name = :name; Array ( [:name] => cron ) in lock_may_be_available() (line 167 of /data/sigrok.org/apache/blog/includes/lock.inc).