I don't use this account anymore; please see @Deskana.
Feb 13 2018
I disabled a lot of gadgets that I didn't even know I had enabled, and it's gone away.
Feb 12 2018
This bar also appears to appear in some other circumstances, too. Here, I tried editing the sandbox directly rather than adding a new section. Perhaps it's to do with whether the page being displayed is long or short?
Sep 29 2017
Aug 30 2017
Aug 29 2017
What's missing here is the "why". Why should the IP be shown to the user? What information does it provide to them? What can they do with that information?