This also occurs on my Dell Studio XPS 1640. I found that you don't need to kill X to regain functionality of the keyboard; just move to any virtual terminal (i.e; tty) using Fn+F# & back toX on F7.
@Zach: I cannot confirm this on my laptop! P.S.: some of you might also be affected by the following bugs: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/969453 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/41301 Description: Ubuntu 12.04.1 LTS Release: 12.04 3.2.0-33-generic amd64 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/962402 Title: keyboard stops responding after backlight toggle To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/962402/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs