afni.nimh.nih.gov

I guess you are right, Tom (much as it hurts to say). But then what's the problem? Perhaps it is truncation artifact, and the dataset should be converted to float before it is processed? That could be done with a command like

3dcalc -a nor008+orig -datum float -expr 'a' -prefix nor008_FL

and then processing nor008_FL+orig with 3dFourier.