[Freesurfer] nu_correct crashing when run within perl.

I am trying to run nu_correct inside of a script using perl. It keeps crashing with a "Termination Status=512".

Processing:.................................................................DoneNot implemented yet in cache_volume_range_has_changed() Not implemented yet in cache_volume_range_has_changed() Processing:.................................................................DoneNot implemented yet in cache_volume_range_has_changed() Not implemented yet in cache_volume_range_has_changed() Cannot open .imp file: nu1.imp nu_correct: crashed while running nu_estimate_np_and_em (termination status=512)

Anyone have any ideas where this may be coming from?

-Eric