This is a continuation of this problem: http://support.mozilla.com/tiki-view_forum_thread.php?comments_parentId=143818&forumId=1 Basically, if you leave the latest version of Firefox running and you set your auto-sleep time to 1minute, does your machine go to sleep? Mine doesn't. I originally thought the problem was with iStatMenus but after ~2 hours of testing, I narrowed it down to Firefox. This test takes less than 2 minutes to conduct. Anyone else experiencing the same problem?