Shu8i is already aware of this but What I believe is happen is the cpu is taking to long before it scales up. What you end up with is the phone lagging as you unlock it. Impatient people such as myself(total dig at myself) will press the unlock numerous times in a matter of seconds.
I keep saying this but the sampling rate is set too high and the cpu load threshold is also too high.. so until it hits a 95 percent load it wont speed up. So the phone is waking up while its at 245 mhz if thats what you have it set to!
this is just my theory. I am not a dev just what I have seen.