Hello Max,
I think you may be running into a Windows 2008 issue where by default it is forcefully unloading the user registry at user logoff.
Can you please enable the Windows 2008 policy: "Do not forcefully unload the user registry at user logoff"?
The policy can be found in the group policy editor (gpedit.msc)
This policy can be found under:
Computer Configuration->Administrative Templates->System->UserProfiles
Change the setting from "Not Configured" to "Enabled".
Regards,
Graham