Shortcut keys and media keys stopped working after 14.04 update

[MPinheiro]

I have a Toshiba Satellite L50-A (and I use an HP wireless keyboard sometimes as well) and I'm using the GNOME desktop. The keyboard layout is currently set to English (US).

Before upgrading to 14.04, I had no issues with keyboard shortcuts (i.e. Ctrl+Alt+t and others), function shortcuts (Fn+F2 to raise brightness and others) or media keys (such as a volume toggle on my wireless keyboard. However, once I upgraded, they all stopped working. All of them. I tried assigning new custom shortcuts via Settings->Keyboard->Shortcuts but this did nothing. I looked at dconf-editor and the shortcuts seem to be properly assigned there. I also checked to make sure that the keys were being properly detected and this seems to be the case.

Interestingly, I recently installed a GNOME tweak that added a brightness toggle to the menu bar, and now Fn+F2/F3 works to raise and lower the screen brightness. None of the others are working, however.

What changed in between Saucy and Trusty? I didn't change anything in my settings, and I just ran the upgrade from terminal. Everything seemed to go smoothly otherwise.