Copying (not moving) blog to new URL

I am eventually moving my site to a new URL (same host though) and instead of just moving the blog, I wanted to copy the database to the new site and play around with it while the original site stays the same.

So far, I have created a new database and imported the database from the other site. I changed the DB_NAME in the wp-config.php file, and have also made the necessary changes to ‘site_url’ and ‘home’ through PHPMyAdmin.

I uploaded the site and the home page is working great, and the posts are all displaying, however, when I click to any of the posts or pages, I get a 404 Not Found error.

Any thoughts as to what could be causing this?

So far this post http://wordpress.org/support/topic/68898 has been extremely helpful, but unfortunately does not answer this new problem I am having.