Can we do one more test? It might be nice to be sure there isn't a corresponding library in the Freesurfer directory, too.
Go to some data and run afni, being sure that variable is set and run:
ls -l /Applications/freesurfer/lib/gcc/lib/libXt*
DYLD_LIBRARY_PATH=/opt/X11/lib/flat_namespace afni
Thanks,
- rick
