So this problem has resurfaced. My above 'solution' was apparently only an isolated success. Our lab has generated surfaces using FreeSurfer 4 on both mac and linux machines (and edited the parcellations on each, respectively, staying only on one or the other). On both platforms, running FSread_annot on our manually edited 'annot' files gives the above errors. However, FSread_annot works on the unedited '?.aparc.a2005s.annot' files created via recon-all.

The previous 'success' was using surfaces generated with FreeSurfer 3, so might this be an issue with FreeSurfer 4 compatibility? Have others out there successfully edited '.annot' files and been able to run FSread_annot on them? If so, on what architecture?

Michael