Duplication user icons on Vista login (Welcome) screen

First of all I did a general search on this and all the results spoke about
finger prints readers and vista updates.
However I am using a new desktop that does not have any finger print readers
and Vista already had all the latest updates.

The duplicate user icon appears after I did the following.
Up to this point I only had one account on the machine.

I scheduled my computer to run a program at a specific time on a specific
day each week and I did not want to login with my main account to do this.
I am also concerned about power usage and heat so I do not want to leave my
main account logged in all day and lock only to run a certain application
for 1 hour.

I have successfully done this on my previous computer with windows XP.

1. Set the bios to power on at a specific time a certain day each week
2. Create a standard user account in windows and set it to auto logon
3. use "net user" to restrict the logon time and days of that standard users
account so that it only auto logon to run the task. (Auto logon will be
denied at all other times when the computer is turned on)

So I did the above in Windows Vista and for the most part it works, except
that after using "net user" to restrict the logon hours the standard user
account that I created is now shown twice on the Vista logon screen.
Like previous post concerning this issue, either icons logs onto the same
profile. Only one user account with that name is shown in the control panel,
users and groups snap-in and "net user".

I found this annoying to I user the SpecialAccounts registry key to stop the
account from displaying on the Vista login screen... Although this had the
effect of hiding the user account from Control Panel users.. There is still
an icon representing that user on the Login screen

Does anyone have any idea how to fix this.

Desktop Computer
No finger print reader
Windows Vista Ultimate 64 bit
Windows is updated