lock screen flashes when resuming from sleep

[citivolus]

I have a minor annoying problem with my Macbook Air. When I open the lid and it resumes from sleep, the lock screen appears for a second, I start typing my password, then the screen blanks out again. I have to hit a key, wait a few seconds, then the lock screen reappears...what gives?

 

[PM-Performance]

mine is weird too if I try to type the password too quickly when the lock screen comes up.
Glitch maybe?