I’ve been dealing with this problem with my Powerbook 12″ lately which has been the source of neverending frustration: while using my laptop occassionally the keyboard will stop working. For a while I thought that the only way to cure my ill computer was to reboot it, and with Google providing no help, I was just about to stick my silver friend in the microwave to teach it a lesson.
Over the past month or so, I’ve discovered quite a few features of this peculiar bug. The first thing I recognized was that not all of the keys were frozen: most of the option and F-keys still provided their full functionality, such as App switching (Commant-Tab), brightness control (F1-F2), etc. Still nothing would repair this ailment, and I’d eventually end up rebooting.
But last night I made a major breakthrough: while locked, I tried to Force-quit (Command-Option-ESC), and suddenly my keyboard was returned to normal. I quickly tried seeing if it was related to any of my running applications: not iTerm, not BBEdit, none of them seemed to affect it. But, while switching applications once I tried to not use Command-Tab, and low and behold, the problem went away entirely.
Whenever I use Command-tab to switch applications now, there’s a good chance that my keyboard will lock. Has anyone ever encountered this problem before? Either I’m a really peculiar user or it’s something specific about the applications I use (I just reinstalled last week).
Update: I realized that when the machine gets into this state, any Cmd-Tab operation will render the keyboard unusable (until you run force-quit), but a reboot returns things to the normal operation. Relaunching the Finder has no effect, so it’s as if the kernel gets into a state where application switching causes the keyboard to hang.