Currently Being ModeratedAug 26, 2011 12:12 PM (in response to Ea$y)
The option for Mouse Keys may have become turned on. To check for that, go to System Preferences > Universal Access, switch the view to Mouse, then turn Mouse Keys off if it is on.
Note that in that same pane there is shown a keyboard toggle for that feature - press the Option key five times in a row to turn it off or on. If Mouse Keys is the problem, that may have been how it got turned on. You can prevent that from recurring by unchecking that item.