I have gotten whitelite with latest firmware -i think its version 01.01.16.
when I 1st got it it went into sleep mode fine. but after hacking it and adding an external drive it stopped going to sleep. I added the featurepack mgr, snmp server, samba 35 with swat, inetd with telnet, optware, mrtg, etc etc
Im not sure what changed -but upon researching it I found out:
the whitelites have a script that runs called monitorio.sh: this apparently monitors the Disk I/O and controls the LEDS and sleep mode.
this depends on a executable called hdparm. i think its in /usr/sbin. the version of hdparm in version 01.01.16 is broken and always reports the drive as active. this breaks the monitorio.sh script.
the fix is to install optware and use ipkg to install the optware version of hdparm. it is a later version and works. I renamed the original hdparm file and copied the new one to /usr/sbin.
upon reboot it started to sleep again.
also upon a little experimenting I also modified the monitorio.sh script -I changed the parameter "SLEEPTIME" from 10 to 5. this made it go to sleep more like I wanted it to.
I also disabled twonky temporarily as its activity to build its DB would interfere with troubleshooting, but I am going to renable it once im satifisfied with the power management behavior.
I also think its possible to change the LED beahavior through this script- It might be nice to just have LEDS shut off when in sleep mode.
I also attached a 1.5TB WD "green" drive. this very nicely sleeps and awakes when I access it over the network.
I hope this helps people