I have just built 2 new computers with Intel Atom D645GCLF2 motherboards and processers.
The OS is Window XP Pro all of the latest from Microstoft.
I have dowloaded and installed the latest Realtek Audio drivers off Intel's web site.
After I install and reboot the Realtek icon is on the lower right of the task bar and will logoff correctly or shutdown ok.
As soon as I log back in the Realtek icon is not shown in the lower right the logoff will hang. I will have to power off or press the restart button on the case to restart the computer.
Intel suggest to reinstal the os.