At least once a week one of my applications gets all screwed up and typing with the keyboard becomes impossible. Today it's an email in Outlook, last week it was AbstractSpoon's ToDoList. I was writing my email completely fine two minutes ago, then I did some surfing, came back to my email and now most of my keys are remapped to something else.
When it happens, it only affects that specific application instance, and every other application still works fine. And if I close and reopen Outlook then everything's hunky-dory again.