Closure generator problem

Hi all,

I have a problem using Closure generator transform.

I have input data (from csv file) looking like this:

Parent;Child
;A
A;B
B;C
C;D
D;E

and after reading I think I should get after closure generator transformations something like this:

A | A
A | B
A | C
A | D
A | E
B | B
B | C
B | D
B | E

etc

The problem is that I get in output only this rows:
Parent | Child | Distance
<null> | A | 1
A | A | 0
A | B | 1
B | C | 1
B | B | 0
C | C | 0
C | D | 1
D | D | 0
D | E | 1
E | E | 0

Closure generator is configured:

Parent ID field: Parent
Child ID field: Child
Distance field name: Distance

What am I doing wrong?
I'm using version 6.1

thanks