Only user who uploads file via cck file field can access the file

I am using organic groups and gradebook. I have a cck file field in an assignment which uploads the file to the private downloads directory. The file is then protected from anonymous viewers, but it is accessible only to the user who uploaded the file. Other members of their group/role get an access denied error message. The User/Permissions are configured that the appropriate roles should have access to view that file field as well as to view uploaded files and access the private download directory. How do I allow all members of the group/role to have access to view all of the privately uploaded files?