New Post: Gephi/NodeXL - measurement difference (betweenness/closeness)

I am trying to understand how Gephi/NodeXL measures Betweeness and Closeness Centrality or rather why there is a difference in measurement.

A twitter network with 1004 nodes and 2314 edges was sent to me. I measured centrality both in Gephi and NodeXL (directed network). Unfortunately I got two different results:

Gephi:

Betweenness | Closeness

A: 358.0 | 1.0

B: 0.0 | 0.0

C: 0.0 | 0.0

NodeXL:

Betweenness | Closeness

A: 295472,785 | 0,001

B: 91827,372 | 0,000

C: 92674,065 | 0,000

At first I thought the network caused the strange results so I tried to measure the statistics using other networks. It turns out that the network was not the problem. Can anyone explain to me how this is possible?