My first MBLD went never to sleep, tried everything, it crashed after a year and WD replaced it (good service, they even recovered my data). The second one (not sure it was new) showed better behaviour, but even with no users it did not always went to sleep.
Since 6 months now I have a MacBook Air and MBLD never went to sleep again.
I found the reason in the deamon.log (generated under support tab in the MBLD userinterface): My Macbook Air was accessing it every … seconds. I found the setting that should be changed under System Preferences\Energy Saver: tab Power adapter: Wake for WiFi access. unchecked the box. Problem solved.
Maybe this helps?
