Wake on LAN don't work after upgrade to Edubuntu 14.04

[Julian Timm]

Hi
I have updated our Edubuntu LTSP Server from 12.04 to 14.04 today, but now wake on LAN don't work anymore.
I had this problem with every Edubuntu version before and on every version there was another solution to fix this.
On an older Edubuntu Version i used a ltsp-shudown.conf file that forces "poweroff -fp" to shutdown the clients.
On Edubuntu 12.04 i must use this file http://bazaar.launchpad.net/~ltsp-upstream/ltsp/ltsp-trunk/view/head:/client/share/ltsp/nbd-disconnect
in combination with the Realtek r8168-dkms driver.
But using the r8168-dkms driver and the nbd-disconnect file don't fix this problem on Edubuntu 14.04.
Edubuntu 14.04 also shuts down our fat clients (Zotac ZBox / Shuttle DS437) much faster than Edubuntu 12.04 did it. So maybe it uses another way to shutdown the clients and thats why the Realtek network card is completly powered off and don't react on WOL requests?

Does anybody knows a solution for our wake on LAN Problem? Is there maybe a way to use an other shutdown procedure to fix it?

Thx for help :)