I was thinking simply removing from the DOM would be enough, but it isn't.  

When I do this, and then I continue to navigate around my site, it eventually tries to take me to an old URL rather than the actual URL I requested.  Since that URL was removed from the DOM, the screen is just white.

I'm guessing that some page ID or page DATA-ID or something is still lying around somewhere, pointing to the old URL.  Then maybe it fetches my new URL via ajax, sees that the ID or Data-ID or something is the same as a previously loaded page (that is no longer in DOM, BTW), and then says: "hey, I know that ID!  I think you *actually* meant to go to this old URL.  You must not know what you're talking about!"