Scenario: when joining a system to the domain and renaming it, some burp happens, and the local system thinks that it has the original computer name and is joined to the domain. The Domain Controller, OTOH, has the NEW name. Either way, there appears to be a problem with the computer password, too, because many aspects of domain funcitonality aren’t working.

Microsoft’s KB (via Google) yields some options:

How To Use Netdom.exe to Reset Machine Account Passwords
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q260575

How To Use the Netdom.exe Utility to Rename a Computer
http://support.microsoft.com/kb/325354

NETDOM Documentation
http://www.microsoft.com/resources/Documentation/windowsserv/2003/all/techref/en-us/netdom.asp