Hello Anja,
  It looks like you have an older version of the PA.  Your version should be 3.0.5.  If you have that version and are still having problems, please respond back with which Matlab/OS you are using and which SPM.  I'm away from the codebase (out of the country) and will return Tuesday of next week.  I'll do my best to respond, but in depth discussion will have to wait until I return home.

Best,
Ben Wagner