When I run vlock or vlock -a on the console as a normal user, then type in password, FC4 vlock complains: $ vlock -a The entire console display is now completely locked. You will not be able to switch to another virtual console. Please enter the password to unlock. jakub's Password: Error sending status request (Operation not permitted) No error messages were printed by vlock in FC3.
This warning is silenced in audit-libs >= 0.9.3. The audit(-libs) should be probably updated in fc4 too.