GinaStub: Suddenly only "Administrator" can logon!

Hi,

I've developed a ginastub replacement about a year ago and has worked
great on both Win2K and XP SP2. I must have tested on 20-30 computers
at least.

I hadn't used it for months though and now I just did.
To my huge surprise I could only get authorized and logon if I logged
on as "Administrator".
I mean, not even if I logon with a user who has administrator rights. I
had to specifically type "Administrator" (and its password ;-)), or I
wasn't accepted.

To check if it was my custom gina or my system I compiled the MS
original VS6 sample security source project: GINASTUB. After
"installing" and rebooting, I tested again and guess what... it reacted
in the exact same way! Only "Administrator" was accepted.

(of course when I remove the GinaDLL string in the registry I could
logon as any registered user)

So, OK it's not my replacement gina, any gina has this problem. But
what is it!?!?

I have XP SP2, and tested at another computer (very different setup)
and got the same results.

Tested on a Win2K SP4 computer and it worked perfectly.

Could there be some security update that did this to my system?
Some antispyware, antivirus, spam, virus?
Some windows setting?
Etc!
I currently have no ideas how to proceed... :-(


Big thanks in advance for any ideas of how to solve this really
troublesome problem!

.