Im getting this error…

After doing things like updating descriptions, or titles…in, The Ultimate SEO pack etc, im getting this error , it comes up quite a bit… It dpes with other things also, yet not as frequesnt

WordPress database error: [Table ‘girlfriend_wordpress.wp_post2cat’ doesn’t exist]
SELECT cat_ID AS ID, MAX(post_modified) AS last_mod FROM wp_posts p LEFT JOIN wp_post2cat pc ON p.ID = pc.post_id LEFT JOIN wp_categories c ON pc.category_id = c.cat_ID WHERE post_status = ‘publish’ GROUP BY cat_ID

what does this mean…..?

Thank you