The same problem I have with my device. It never sleeps, even after 10 minutes (the option was set up in software). It seems that something waking it up constantly - the LAN indicator keep flashing, and HDD sounds like performing read/write operations (though there was not any active operations!). When I unplug the LAN cable - the device went to sleep mode after 10 min.
Router ASUS WL-520GC, I use static IP.
Would be thankful for any help!
