My F5 key has suddenly stopped working. I have an HP Pavilion dm3 that I bought in Thailand. For several months, pressing the F5 key would 'lock' my user account so that you needed to enter the password to get in. Now it's stopped working. Fn+F5 still works, that basically does an F5 command (For example, refresh in Firefox). But I really miss the functionality of that lock button. Any way to bring it back? Did I delete something I shouldn't have?