I recently had a problem trying to use mysqldump where it was complaining that
This corrupted wp_options table actually caused wordpress to think it was a fresh install, and showed the interface to create the admin user to anyone who accessed recurser which is a little scary :)
The solution was to go to the actual database directory, and run myisamchk -r on the offending table :
1 2 3 4 5 6
After this everything seemed to run normally again. There are a lot of other myisamchk options if this simple fix doesn’t work for you - if the man pages aren’t any help a quick google should reveal loads of info.