It seems that my computer never goes to sleep when blender is open. Even after blender has finished rendering.
I could see it keeping the system awake when it’s rendering but it should go back to whatever the system setting is when the rendering has finished.
I have the same experience on OSX. I have reported it to the dev team and they are looking into it. It is related to the audio system never sleeping. You have to close Blender, launch the ActivityMonitor and use it to locate the CoreAudio process. Terminate that process and your computer should sleep as normal. (Until you open up Blender again).
OK, thanks. I’m on Windows 7.
I filed a bug report. They asked if changing the audio in the Blender user preferences fixes it and it does. I changed it to None since I’m not doing anything that uses audio. So now the bug is tagged for both Mac and Windows.