I've been trying to create new posts on streamhacker.com, and the preview isn't working, it just shows my homepage (and it's not a redirect). If I try to go to the post slug, I get a 404 error. If I try to publish the post, then go to the slug, I get a 500 error (you can see the same kind of 500 error if you go to http://streamhacker.com/2011/04/14/text-processing-api-survey/ even though the post is on the home page and made it into the rss feed). I cannot find any error log/messages to explain what's going on. I searched the forums, but the only suggestion that seemed to fix other people's problem was that the blog URL and site URL should be the same, but that's already the case for me. This was happening in 3.1.2 and continues to happen in 3.1.3.