Passwords must meet criteria that the password policies specify.
Complexities and requirements in Windows 2000/2003 password policies are different from complexities and requirements in eDirectory.
If you plan to use Password Synchronization, create and use passwords that match the rules of complexity in both Active Directory and eDirectory. Otherwise, the passwords fail.
HINT:Make the password policies for both systems as similar to each other as you can. In a lab environment, disable strong-password functionality on Windows 2003 servers before installing the Active Directory driver. After the Active Directory driver is working properly, make sure that passwords used in eDirectory and Active Directory satisfy the rules of complexity for both systems. Then re-enable strong-password functionality on the Windows 2003 server.
For troubleshooting tips, see TID 10083320.