ArtChess 0 Junior Poster in Training

Okay so i'm going through this CBT nugget and i'm now on redirusr command - I am able to do it but it doesn't seem to go to a OU within an OU.

Scenario
Computer I am using vm Windows 2003 Ent Server - acting as a Windows 2003 Server in a AD domain - with highest elevated right.

Wyhen i go to command:
redirusr OU=TEST,DC=VMField,DC=COM [ENTER]
successful

however when i do
redirusr OU=TEST,OU=Userz,DC=VMField,DC=COM [ENTER]
Error, Unable to modify...functional level of the domain....


Sooo, What to do what to do??