That's fine but it only centres horizontally. Usually when people talk about "the div centring problem" they mean x and y, dead centre (as this article is).
The article only seems to very briefly mention the vertical axis, with pretty much all of it focusing on interactions with the sidebar (which only affects the horizontal width).
The article only seems to very briefly mention the vertical axis, with pretty much all of it focusing on interactions with the sidebar (which only affects the horizontal width).