This shouldn't be surprising; most sites do exactly what this site does (if you don't believe me, go to any Wikipedia article, click an entry in the TOC, and click the back button; you'll probably go back to the TOC, not all the way back out of the article). That's how it should work, and I was pleasantly surprised to see that this framework preserves that.

One thing NatUIve does appear to get wrong is that (at least with JS enabled) if you use the forward button too rapidly it'll get confused and renavigate to the page/tab you're on, thus preventing you from going further forward (because it adds an extra entry to the history). This doesn't happen when you turn off JS, so I'm pretty sure it has to do with the scroll effect.