Users can't see upload field. Admin (user 1) can.

Hi,
I've taken over a site and found that the video upload content type wasn't working - no upload field was visible. I've set up the appropriate CCK field types, and it now seems to be working - but the upload field is only visible to the Drupal super admin, user 1, when creating content. Other users can't see it.
I have excluded the fields in Display Fields. Is that relevant? I tried unexcluding the first Upload Video field, but that had no effect.
Cache has been cleared...
I don't see any obvious permissions to set anywhere...
Thanks for any help.