Database error: [Got error 28 from table handler]

Everything was working perfectly fine before I left for my weekend getaway, and I have just returned to see if I have recieved any comments on my last post, and to put in a new entry only to find the following error –

Database error: [Got error 28 from table handler]
SELECT * FROM wp_posts WHERE 1=1 AND YEAR(post_date)=2004 AND MONTH(post_date)=07 AND (post_status = “publish” OR post_author = 1 AND post_status != ‘draft’) GROUP BY wp_posts.ID ORDER BY post_date DESC LIMIT 5

I check in my admin panel and I see the same error, plus none of my posts are showing, it says that there are no posts found.
What does this mean, and how do I fix it, and how the hell did this happen? I really need to fix this and I dont know how.
Aidan
http://www.early-frost.org