SYMPTOMS

If you log on to an MIT realm, press CTRL+ALT+DELETE, click Change Password, type your existing MIT password, and then type a new, simple password that does not pass the dictionary check in Kadmind, you may receive the following error message:

Your password must be at least 18770 characters and cannot repeat any of your previous 30689 passwords. Please type a different password. Type a password that meets these requirements in both text boxes.

Note that the number of required characters changes from 17,145 to 18,770 with the installation of SP1.

NOTE: This is not a common case; it occurs only when you configure Windows 2000 to authenticate against an MIT Kerberos domain.

via microsoft.com