I just reproduced it following the commenters instructions -- clicked the sidebar link, got a popup, pressed the back button and I have no scroll bar. I can se

I just reproduced it following the commenters instructions -- clicked the sidebar link, got a popup, pressed the back button and I have no scroll bar. I can see what is happening there: the popup removes scrolling (because of the overlay) but the back button doesn't restore it. This certainly does lend to the conclusion that managing page state in a SPA is not trivial.