SOLVED: The Firefox extension "FoxTab 1.4.5" was responsible for breaking these shortcuts. Disabling it restores the desired functionality.
Previously, on Ubuntu and other systems, the following shortcuts in Firefox would work:
- Ctrl + Tab - Switches between tabs
- Ctrl + F4 - Closes current tab
Since installing the Mate desktop (Gnome 2), the shortcuts do the following:
- Ctrl + Tab - Does nothing
- Ctrl + F4 - Closes Firefox
I've checked in the "Keyboard Shortcuts" section in Mate, but neither of these are being overridden. Compiz isn't installed.
This is rather annoying.