I was having the issue here (logintoboggan/file_permissions combo): http://drupal.org/node/1722134 which is now patched and fixed. However, I have several fields that are set to 'View anyone's value' but those fields are only showing to logged in users.
If I disable field_permissions module completely, they re-apprear for anonymous users so it has to be an issue with some permissions getting messed up?
Is there a way to clear/rebuild the permissions in the db to see if that fixes things? any other suggestions for getting this working would be great as there are some admin only fields I have in places which really need hiding but the rest needs to be visible.