404 on front page after migrating site

Hi, I just copied all the files (wordpress/, index.php, photos/, data/) for a site running WP-2.0.1 with K2 and other plugins over to another host, and also exported/imported the entire MySQL database. I then updated the options ‘siteurl’ and ‘home’ and wiped out the cache (mv wp-content/cache{,.old}). However, now I always get a 404. It seems all the data is there and all other pages function fine, though (I can read posts, log in, etc.). I realize that this is probably not a lot of information but how do I tell what’s going on? I tried reading some PHP but it’s a lot of code. Please help, thanks in advance.