Macbook pro 15" keyboard freezes only function keys work

Question

I am facing a very weird problem with my MacBook Pro 15". I was working in Xcode 4.2 and when I option-click in simulator (to simulate multi tap) my keyboard stops working. The weird thing is that only the a-z and 0-9 keys are not working...

By the way I am using a bluetooth mouse... and recently updated my system to MacBook Pro EFI firmware update and I am running OS X 10.7.2 Lion.

I had to restart my system to get the keyboard functionality back.

Is this a bug in the OS? How can I get rid of this problem?

Thanks in advance

Answer 1

Finally got it. I was pressing option keys lot of times and pressing it 5 times enables mouse keys (which disables keyboard keys).

To reverse, go to "Settings -> Accessibility -> Mouse and Trackpad" and uncheck "Press the option key five times to turn Mouse keys on of off" or simply uncheck "Enable Mouse Keys."

Answer 2

Note: This issue (function keys only working) can occur using the Apple wireless keyboard with an iPad as well. Unfortunately, iPads don't have the same Accessibility settings mentioned above. Replacing the wireless kb batteries (thus powering it down completely) and disconnecting/reconnecting the keyboard connection did NOT have any effect correcting this problem. However, powering down the iPad completely seemed to do the trick; after cold boot of iPad, the standard keyboard keys were re-enabled.