WP Newbie

Everything was working perfectly forever and now I get this message. I don’t know how to fix this. I’m using yahoo small business as my host. I’m a rookie and have used only the basic setting that yahoo offer. Here is the error I recieve.

WordPress database error: [Can’t open file: ‘wp_postmeta.MYI’ (errno: 145)]
SELECT post_id, meta_key, meta_value FROM wp_postmeta WHERE post_id IN(184,181,179,178,177,176,175,174,173,172,171,170,169,168,167) ORDER BY post_id, meta_key

Thanks for any help.