Vista - ScreenSaverGracePeriod setting in registry

1) Is the ScreenSaverGracePeriod setting supposed to work in Vista, as in
http://support.microsoft.com/default...b;en-us;221784 ?

We have a group policy that sets this REG_SZ value in
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon, and
it works in Windows XP, but it does not seem to have any effect in Windows
Vista.

I have tried it in:
Windows Vista Business SP-1
Windows Vista Enterprise
Windows Vista Enterprise SP-1
Windows Vista Enterprise SP-1 64-bit

As an experiment, I tried it at HKEY_CURRENT_USER\Software\Microsoft\Windows
NT\CurrentVersion\Winlogon and it seems to work. This may actually be a
better place to put it (a user setting), but is not documented.
2) Can I expect it to continue working?
3) Any idea if it will work in pre-Vista versions? (I haven't tried it
yet.)
4) Is HKEY_LOCAL_MACHINE\Software\Microsoft\Windows
NT\CurrentVersion\Winlogon\ScreenSaverGracePeriod supposed to override
HKEY_CURRENT_USER\Software\Microsoft\Windows
NT\CurrentVersion\Winlogon\ScreenSaverGracePeriod, or vice-versa?

1) I routinely create the HKLM REG_SZ value you described on all of my work machines to give myself a 300 second grace period between screen saver init and logon prompt. This has worked fine for me with all versions of Vista that I have applied it to (Ultimate, Enterprise, and Business + SP1 + x86 & x64editions).

It never occurred to me to try to place this in HKCU so I cannot attest to if that should work or what the order of precedence might be in the event of conflicting settings (but I agree that it probably does make more sense as a user setting).

One thing that may differ between what you are describing and my scenario is that our domain GP does not attempt to set this value; it just enforces a more basic rule that a password protected screen saver must be used and limits idle time to a mazimum of 10 minutes. Creating this setting manually definitely gives me the ability to escape the screen saver and bypass the logon screen if I catch it quickly enough.

Does your GP override this setting by any chance? You might try setting it and then running gpupdate to see if it gets changed back (and don't forget that any changes you or the GP make to this setting won't become active until you log off and log back in).