This is a really weird one and we're going nuts trying to determine what the cause is. We have a theme we built but we're not even touching the logic for URL rewriting. That's all handled by WordPress itself.
We'll add an article and check some categories to apply it to and it will add and link correctly from the homepage, yet we'll do the same thing for another post but this time the link generates and shows data on the homepage, but we cannot click through to the article itself. It's coming up as a broken page.
Any advice is appreciated. Thanks guys.