Bug in ADSIEDIT.DLL causes ADUC crash

Apparently a bug in ADSIEDIT.DLL can cause ADUC to crash in certain scenarios when running on an AD with a schema upgraded to WS08. The error message is "MMC has detected an Error in a snap-in. It is recommended that you shut down and restart MMC."

See KB 946459.

KBAlertz.com: In an Active Directory forest that is running a Windows Server 2008 schema, the Active Directory Users and Computers MMC snap-in may crash when you open the Properties dialog box for a user object from a Windows Server 2003 member server