require user to Ctrl+Alt+Del to enter Vista Business

I've got a new laptop running Vista Business. Once I booted the machine,
I went into Advanced User, and saw that the option to require users to
Ctrl+Alt+Delete was greyed out.

I proceeded to join the pc to the domain, and when the screen came up it
was at sign-on, no Ctrl-Alt-Del.

I launched gpedit.msc on the laptop and changed the Interactive login:
Do not require CTRL+ALT+DEL to disabled. On first reboot it worked, but
on subsequent reboot it changed to enabled.

I then launched Domain Policy on server and set Interactive login: Do
not require CTRL+ALT+DEL to disabled.

It worked on first bootup on laptop, but not subsequent.

How do I change the checkbox for "require users to Ctrl+Alt+Delete" ?

Also I can no longer change the Local Policy for Interactive login: Do
not require CTRL+ALT+DEL, it is also greyed out.

fwiw I've signed on as both domain admin and local admin...

Jeff