Sorry, I forgot to mention the environment right away. I discovered it on Gentoo Linux 3.6.11-gentoo x86_64 with firefox 19.0, plugins enabled: AdBlockPlus, Clear Fields, Fox Clocks, Tile Tabs, Tree Style tabs. I also reproduce it with clear firefox profile and addons disabled.

But I discovered that the OT tab have to be Pinned as App, regular tab will not make colored notification.

Unlocking settings works as expected, without activating shortcuts.

[VERIFIED]