Tested: Working
Model: WL-500g
Firmware: 1.9.2.7-7e

Device:
Brandname: Coolermaster ( Cooler Master )
Brandtype: Xcraft RX-3HA
USB Interface: USB 2.0 High Speed (480Mbit) compliant
Firewire Interface: Firewire (400Mbit)
URL To manufacturer: http://www.coolermaster.com/
URL To product: Click

Device Used during test:
Brandname: Maxtor
Brandtype: Maxtor Diamondmax Plus 10 250GB
Brandmodel: 6L250R0
Size: 250GB
partition: 4GB using FAT32 (worked the first time)
partition: 245GB using NTFS (backup purposes, not via Asus WL500g)

No spindown while connected to WL500g
Does spindown wile connected to Laptop (firewire)
USB connecton (spindown) to laptop has to be tested soon.