It affects me too. Ubuntu 16.04.1 (64-bit) with Unity. Please note: it's more visible with GTK dark themes. I'm using Arc Dark Theme. This happens with light themes too, but it's subtle with them. But with dark themes is very prominent.
Arc Dark Theme: https://github.com/horst3180/arc-theme Firefox Arc Dark Theme: https://addons.mozilla.org/en-US/firefox/addon/arc-dark-theme/ Using NVIDIA binary driver 361.42 from nvidia-361. (GeForce GTX 960) ** Changed in: firefox (Ubuntu) Status: Expired => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1576605 Title: Activating menu items creates permanent space between title bar and tabs To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1576605/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
