Reply bug?

I tried o reply to a message by Big John and got this:

user warning: Table './drupal5/watchdog' is marked as crashed and should be repaired query: INSERT INTO watchdog (uid, type, message, severity, link, location, referer, hostname, timestamp) VALUES (4, 'content', 'Comment: added My email.', 0, 'view', '', '', '', 1217721659) in /usr/share/drupal5/includes/ on line 172.
warning: Cannot modify header information - headers already sent by (output started at /usr/share/drupal5/includes/ in /usr/share/drupal5/includes/ on line 309.