Javascript Disabled Sections
They don't deprecate well.
Normally, there would not be an issue. With Javascript disabled, the [hide] and [top] links would just do nothing. However, if we have the pretty URLs active, these links send us the site main page.
What we need to do is only add these links if the browser has Javascript enabled. That means the browser has to create them somehow. This occurs in a number of special pages and templates and not merely in usage of the [h] BB-Code, so this probably won't be fixed until 2.1.0.