I've been having this problem for awhile now where, about once every 24 hours, my LS-CHL (500gb) just disappears off the network. I would say it is going to sleep - like it was on the "Auto" power setting - however, it IS NOT on the Auto power setting - it's on manual.
I can simply unplug the network cable and plug it back in, and it will wake back up. Or I can shut it down and reboot it - which is a pain if you have downloading in progress through the bittorrent client (because then you have to wait for that to update again.)
Do I have a faulty unit? I am on firmware 1.07. I know there is a 1.21 firmware out but I'm all Mac-based and can't easily update (tried using Sun Virtual Box and Windows XP but it doesn't see it on the network - the NAS client does though.)