Post.php no longer working

I set up a blog for a client and all the sudden he can no longer post. He writes his post, clicks “publish” and waits for about a minute (literally) to either get a blank page, and the post the submitted was not actually submitted. I havent messed with any of the code on the blog at all so I have no clue what is causing this. Any idea? I think the request might be timing out.