Auto Standy doesnt work! - My Book Home 1TB Win 7

Hi Guys

I used this drive on my main pc via firewire and it would standby when not in use. I’ve now moved it to a nettop running win 7 with USB and the drive never goes into standby! It’s always whirring but the lights do not go up and down. I have updated to the latest firmware and also have wd drive manager installed.

Anyone have any ideas whats going on? I would assume that when the lights are breathing, thats the standby feature.