Since my original message I tried to align the two anatomies with an earlier version of afni (from April 9, 2007). That version processes the files ok.
I wonder if there is a problem with the new version and oblique datasets? I see all the warnings about using '3dWarp -deoblique'. I didn't try that as a fix because I had succesfully aligned these two anatomies with an earlier version of afni and it worked fine.
Is it possible that I just didn't wait long enough for the new version of afni to process the files? I waited about 4 hours which was way longer than it had taken in the past.
I am happy to use the older version of afni to process this dataset if that is the solution. But I would prefer to use the latest version of afni if at all possible.
Thanks,
Christine