Vista Clients not sleeping as per group policy
I'm trying to set our Vista clients to 'sleep' after 5 minutes of inactivity (cost cutting). I've set group policy under
Computer config > Admin Templates > System > Power Management > Sleep Settings
so that 'Specify the System Sleep Timout' is enabled and set to 300 seconds and 'Allow Standby States S1-S3 When Sleeping' is enabled.
Despite this, they do not sleep. Group policy is fine as our start menus and desktops are redirected via GPO fine.
Any ideas on what may be stopping them from entering a sleep state? The NICs are set up to allow WoL so I can script them to turn on / shut down, could this be a cause?