I've had problems sleeping my Mac since upgrading to Mavericks. It wakes up every hour after I sleep it. I just noticed that the /var/vm/sleepimage file has last been modified on Oct. 23, the same day that I upgraded to Mavericks. I suspect that for some reason, when I sleep my Mac, it doesn't write to the file anymore, so my Mac never really sleeps. So, could someone with Mavericks and who either sleeps their Mac regularly or who is willing to sleep it now (then wake it back up immediately), please go to the Finder, then select "Go -> Go to Folder" and type "/var/vm", then tell me the "Date modified" for the "sleepimage" file that should be in there? Is it a recent day like today or yesterday, or is it also the date that you upgraded your Mac to Mavericks? This would help a ton! Thanks in advance!