Clustering

I was told that if you want a cluster and say you have.
Barren
barren
baren
Spaz
Barren

And you want the spazz bottom, you select the planet code on top to cluster is above.

i did this:
http://img337.imageshack.us/img337/1131/problemdw.jpg

but this did not happen instead in went to the bottom and with another code
E.1736 U.Spazial 13 14 25 1 2 0 Rutile
C3.1466 Similare C.3 7,980 3,990 24 0 7,780 54 Terran Metal

did i do something wrong?