Computer freezing after it goes to sleep?

[Cata|yst]

Whenever i start my computer after it has gone to sleep or entered screen saver mode, my computer would just freeze. the only fix is that is that i would have to power off it =[.

One time, when i tried to open up Task manager, i got a message saying something like "failed to start up security bla bla" I wasnt able to paste the s/s, as i had to power shut it.

What could be causing this?

[ARandomGuy]

Are you running vista?

If so, try updating if you haven't with hotfixes that could solve your problem. This one should work: http://support.microsoft.com/kb/943899

The task manager might be a different problem. Try this thread to info: http://www.vistaforums.com/Forum/Topic13079-9-1.aspx