That was fixed with the latest version of the skype block.
But now there's another problem:
The names shown drectly as online can be skyped via clicking on the link, but beneath there's a link "Students on Skype": http://screencast.com/t/4t20oEAM
When clicking that link the result is as shown here: http://screencast.com/t/IwtUGMUp7HI
Anyone who knows what the problem might be?