I just go my two new flashes from amazon, 600EX RT

Questions: (when using RT)

Groups: In setting up Groups (Gr) only certain "cameras released after 2011" are capable of this function.
Should I be able to do this with the 5D mark II?

What I want to do is set up the on camera as ETTL and the off camera as Manual (like a hair light).
This function is available in Groups. But I am not able to set this up with the 5D Mark II.
Am I doing something wrong?