We have just put our company image on to the 840 and everything appears to be going well apart from a random freezing issue after the laptop is woken up from sleep. I've been unable to replicate it consistantly.
Windows 7 Professional x64
Driver pack for SCCM from HP
I've read similar issues where the laptops wont resume from sleep at all, but this is different. It gets to the Ctrl alt del screen but then you cant log back in to the device unless you reboot. I have installed a previous release of the display driver (see http://h30434.www3.hp.com/t5/Notebook-Lockups-Freezes-Hangs/HP-Elitebook-850-Black-screen-after-sleep-mode/m-p/3398165#M48649) and it still exhibits the same behaviour.
You can hear windows working away (recognising devices, emails coming in etc) so it's not a full freeze, it appears to be GINA just not accepting the ctrl+alt+del keys. The only thing I can see in the event logs is our VPN client (cisco) being unable to find a network address and e1dexpress saying the network is disconnected.
Has anyone else seen this type of behaviour?