We have been seeing a lot of issues with TokenLock which are Lion related. Apple has changed a lot of stuff in Lion and in doing so has introduced some bugs, and some different behaviors.
10.7.1 - System lock also runs the screen saver, but with no password. The result of this is we have a hard time determining whether the saver or system lock is active. By default we now make the lock a screen saver lock.
DisplayPad randomly kicks off the screen saver with 10.7 - causing some folks to wonder if this was Tokenlock.