For a while, I have occasionally had my MacBook Pro panic when I unplugged the USB cable. For you non-Unix geeks, that means the machine stops--dead--and has to be rebooted. OS X hides the reason from you. Even when you restart, it simply asks if you'd like the problem reported to Apple.
However, if you push the right buttons on the dialog box, you can see the dump. When I did this, I discovered that it was the Logictech Control Center that was causing the problem. LCC configures Logitech mice and keyboards. I did the usual thing and updated to the latest driver with no joy. So, I did the natural thing: I bought a new Apple wireless keyboard and that solved the problem.