If you’re running Windows 2008 Server on a VMWare ESX host with VMWare tools installed, make note that the Windows 2008 Server VM can sync its clock to the ESX host, even if you disable this option in VMWare Tools.
I recently experienced this in an Active Directory environment, and of course the Windows 2008 Server VM was also a domain controller, so it made things stop working for about a half an hour before we could actually pin point what was skewing the clock so badly. Turns out, our ESX host had NTP enabled, but this was syncing the clock 2 hours wrong, and the 2008 Server VM automatically set its clock to this on each reboot.
Disabling the NTP-service on our ESX host and setting the time manually fixed the issue, but of course this is not a good work around.
Update: check out John’s post in the comments bellow for a fix for this. Thanks John.