Error 15401 - Adding AD User To SQL Server

All,

The current setup is as follows:
SQL 2005 64bit v9.0.3054
Windows 2003 SP2

Problem: When trying to add an AD user to SQL, I receive error 15401

Background: The user's last name was recently changed and so all relevant AD fields were appropriately changed:
Lastname, Displayname, E-mail, UserLogonname, UserLogonname (pre-Windows 2000). The user's previous email account has not been changed except for additional email addresses to account for the new name and old name. Also note, the uses Exchange alias is still the previous account name.

When I enter the user's new account name into the Login Name field in SQL I recieve the 15401 error. When I do a search for the user's new account name SQL finds the previous account name and not the new one. I have reviewed KN 324321 and that article does not resolve this error. The user account can be found be only using the original account name and not the new one.

On the same SQL server, I opened the security settings for a folder and added the new user's account name and it was found. I then had it search for the user's old login name and it could not find it.

Any help would be appreciated...

Regards,

Ian