XPS 15 (L521X) not sleeping/hibernating after upgrading to Windows 8.1

The computer is set to the Balanced power profile and it is set to sleep after 30 minutes on AC Power and 15 minutes on battery screen black out works perfectly Yesterday I used my computer and was not feeling well at one point so I took a nap for a few hours and when I woke up the screen was black but the power indicator was solid white meaning it was still running.  When I press a key or use the touchpad the screen comes back on and shows the Windows lock screen.  The computer will sleep and hibernate if I close the lid but if the computer is left open it never sleeps.  It worked perfectly fine before 8.1 so I am thinking it has to be something with 8.1.  Windows 8.1 is new and it doesn't even show up in the list of operating systems when I visit the drivers and support site using my service tag.  Do I need to wait for Dell to release a new BIOS update or Quickset?  I have the July version of the BIOS which is the latest one but the latest Quickset is 2/5/2013.  Is this a known issue?