Lately when I walk away from the computer and it goes into sleep mode, I come back and try to us the computer, all the applications are stuck "not responding".

I can use the computer and browse around, but any application that was open before going to sleep is now stuck. If I try to open Chrome after, it takes forever and 300% CPU. I have to force quit all the apps. Then I reboot (which also takes a long time).

I have 8GB of RAM on my macbook pro, i7. It only started to happen in the last couple of days. I am running Lion.

UPDATE: I now suspect something about the process called "qtkitserver". It happened today without going to sleep mode. One thing in common also was that uTorrent was running. I read online that QTKitServer is responsible for video thumbnails I think - maybe connected to the fact that I'm downloading videos.

  • When did you install Lion? Just before this started happening? Could be a memory leak in one of your apps - is Activity Monitor reporting high CPU or RAM usage for anything?
    – dan8394
    Aug 2, 2011 at 16:03
  • It started happening a few days after installing Lion - not immediately. I doubt it's a memory leak in one of the app because ALL the 3rd party apps are stuck, but the OS itself is fully responsive. I will look again in Activity Monitor next time it happens.
    – nute
    Aug 2, 2011 at 17:14
  • "kernel_task" seems to take around 15% CPU and right now 650MB RAM (the system hasn't crashed yet).
    – nute
    Aug 2, 2011 at 18:54

2 Answers 2


You might try seeing if trashing any files that have windowserver in them from ~/Library/Preferences/ByHost/ and seeing if that helps to temporarily remedy the issue.

I would expect this to get cleaned up in an official patch once it's certain these files are causing some of the sleep/wake sluggishness - but I've seen anecdotal evidence that this works for some.


Have you tried repairing disk permissions and reinstalling Lion?

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .