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I have a Macbook Air with Lion. "Most of the time" / "Intermittently", when I plug in a USB device, the built-in keyboard/pad stop working. I find this fairly frustrating.

Does anyone know what's wrong?

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Any USB device or a device in particular? – Gerry May 31 '12 at 7:40
@Gerry I don't own all that many USB devices. So far it's happened with a mouse and with headphones (may have happened with a keyboard, but I plug in the keyboard when the built-in keyboard has already stopped working, usually...) – Trevoke May 31 '12 at 12:20
up vote 1 down vote accepted

Interesting situation, I'd try booting to Safe Mode (you can follow the relevant instructions here)

It sounds like there's an issue with your kernel extension caches, which booting to Safe Mode will clear, along with generating new kernel extension caches.

Let us know how you go!

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Done. So far so good. I'll mark this accepted in a few days if the problem does not return. Thanks already! – Trevoke May 31 '12 at 12:29

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