Alt - Shift - S keyboard key sequence does not invoke the secure lockdown SW

I have no antivirus SW running . I am running the Secure Lockdown on an XP Professional machine.
I have enabled the Secure Lockdown but I cannot disable it now. The Alt-Shift-S keyboard key sequence does not cause any reaction from the SW.
Did anyone have a similar experience?
Thanks.

Are you logged into the same account as the one you locked down? The account also needs to be an administrative account.

Thank you for your quick answer.
Yes, I have only one account which has administrator rights.

Got the same problem. I only have 1 account which is admin, but the alt+shift+S doesn't show the window. As you can probably figure, I used this to log in and out multiple time and eveything worked well. Now I'm totally locked out. Start Menu is empy, can't launch anything with keyboard shortcuts as it gives me the warning that I'm not allowed... even in safe mode.

So what are my options now ?

I was able to create a new user by booting in safe mode with command line. If someone needs the info:

net user UserNameOfNewUser PasswordOfNewUSer /add

To make it admin :
net localgroup administrators UserNameJustCreated /add

Note that my system is french so I had to replace administrators by administrateurs.

So I now have an account with admins right but the original account's still not working...

Working !

Seems like it has been remove from the startup items or whatever. I noticed that Microsoft Security Essentials was activated and there was a McCafee thing too. Maybe it was there from the start but only scanned like 2 weeks later.

Anyway with the new user I created I was able to place a shortcut in the startup folder for the locked out user. Everything is fine now. Internet Explorer launch upon login and ALT+SHIFT+S works again.

Hope this thread can help the OP and other as well.

Spoke too soon. Seems like it was a one shot deal. ALT+SHIFT+S doesn't work anymore. IE isn't launched either...

If you are running anti-virus software, it is likely blocking the Secure Lockdown configuration utility from launching (Alt-Shft-S). Microsoft Security Essentials works fine with Secure Lockdown.