Torgny has located the problem.
Thanks, Torgny!
What is the right approach to fix this?
Best regards,
Adrian
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  Adrian Aichner              Teradyne GmbH, European Design Center
  Integra Test Division       Telephone +49/89/41861(0)-208
  Dingolfinger Strasse 2      Fax       +49/89/41861-115
  D-81673 MUENCHEN            E-mail    adrian.aichner(a)teradyne.com