Unable to get Autologin override to work properly on Windows 7 Pro 64

in our current environment we have about 150 PC's setup to autologin as a restricted account.  They are basically kiosks, with very limited access to everything (no proxy, no network drives, no cmd prompt, no right click etc).  I want to upgrade them all to windows 7 64, and am struggling with autologin.

autologin from systinternals does not work on 64 bit because it modifies the 32bit subsection of the registry file here:
HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\Current Config\WinLogon 

I have succesfully made a machine autologin, but when I hold shift, it will not override.  I need to be able to log into these machines as administrator in order to support them. 

the keys that I have been changing:

HKLM\SOFTWARE\Microsoft\Windows NT\Current Config\WinLogon
AutoAdminlogon 1
DefaultDomainName  *****
DefaultUserName   ******
DefaultPassword ****** 
ForceAutoLogon 1   

If i set ForceAutoLogon to 0 it will automatically log in at bootup.  If a user selects logoff then it will go to a login screen.  I want it to Autologin when a user selects Logoff, unless shift is held.