Today I visited my site and there were no posts. So, I checked the database, and PHPMyAdmin told me that wp_posts had crashed and the automatic repair had failed. I did a manual repair and now the table is fine and the site comes up normally.
The odd thing is that all of the user-defined dropdown menus are gone. There were 3 of them, now the total number of menus is 0.
Where could they have gone? Where are the user-defined menus stored? Is it in wp_options?
I need to reconstruct the menus, and I really can’t do that from memory.
Menus are stored in wp_options. Sounds like the database is toast. Do you have a backup? No? Does the web host have a backup? Ask them.
If the database is toast and the web host doesn’t have a backup, unfortunately it’s a hard lesson about making sure you have your own backups. Always have a database – and preferably a theme and uploads backup – at all times. Pick a backup plugin and use it: http://wordpress.org/extend/plugins/search.php?q=backup