[igraph] Problem whith betweeness centrality

[igraph . x . flushy]

Hi,


I'm playing around with betweenness centrality and get results I do  
not understand and
also can not be correct.
The Graph I'm using is the "Kite Network" by David Krackhardt,
http://www.orgnet.com/sna.html

The Graph is created as undirected graph
  igraph_create(graph, v1, 0, IGRAPH_UNDIRECTED);
And the output of the complete network as dot is as follows

graph {
  0;1;  2;  3;  4;  5;  6;  7;  8;  9;

  1 -- 0;  2 -- 0;  3 -- 0;  4 -- 1;  3 -- 1;  2 -- 1;  3 -- 2;  5  
-- 2;  6 -- 2;
  4 -- 3;  5 -- 4;  7 -- 4;  5 -- 3;  7 -- 5;  6 -- 5;  8 -- 6;  9  
-- 8;
}

The values calculated for all node are (  igraph_betweenness(ygraph- 
>graph,&res,igraph_vss_all(),0))
(First column: Node id, second column: name as on webpage; third  
column betweeness calculated

0 Carol: 0.00000
1 Andre: 1.08333
2 Fernando: 8.58333
3 Diana: 2.16667
4 Beverly: 2.33333
5 Garth: 9.83333
6 Heather: 14.00000
7 Ed: 0.00000
8 Ike: 8.00000
9 Jane: 0.00000

and are obviously wrong as for example the value of node 2 (Fernando)  
and node 5 (Garth) should be
identical.

What am I doing wrong or is their a bug?


Thanks in advance
I.