Cause of the brightness/volume reponse delays?

[debkmaillist]

robert at elastica.com writes: 

> I recently saw some thread about speculation on the response times before
> brightness and volume adjustments actually take affect. More specifically
> there's a delay incurred prior to seeing anything on the screen aftering press
> either volume or brightness keys. Someone suggested this was introduced by a
> 10.2.x update. 
> 
> 

I just set up a new TiBook Saturday, updated immediately to 10.2.6, and have 
not seen any delay in response time when changing brightness and volume via 
the keyboard.