Dear Rick,
After all what you have said, it just doesn´t make any sense that there is a difference for a single paradigm. There must be something wrong in my scripts or I have maybe mixed up different Afni versions. I will try to find the mistake and if I´m absolutely sure that there is no mistake, then I fear I have to poste again. I´m sorry for bothering you so much but thank you very much for all your help and your considerations. Now I know where I start looking for the mistake.
Best regards,
Beate