MB Air takes 20-30 sec to sleep. Is that normal?

[gregor.hoch]

Hi, my 2011 13'' Air takes about 20-30 sec to go to sleep. During that time, the screen is black but still glowing, the mouse is visible and I can move it around. Always seems like eternity and far from instant off...

Is that normal? What can I do about it?

 

[MultiFinder17]

I've noticed this occasionally on my mid-2009 Air as well. Not entirely sure what causes it, but it seems to sleep fine once it finally does get to sleep.