You're right, it was a theming issue preventing the subset from displaying. Thanks for the help.

Another issue I've got now -- after adding a role assignment and submitting it, I get 2 errors returned:

user warning: Unknown column 'duration' in 'field list' query: UPDATE uc_roles_products SET duration = 1, granularity = 'year' WHERE pfid = 4 in C:\www\xampp\htdocs\testdru\includes\database.mysql.inc on line 172.

user warning: Unknown column 'shippable' in 'field list' query: UPDATE uc_roles_products SET shippable = 0 WHERE pfid = 4 in C:\www\xampp\htdocs\testdru\includes\database.mysql.inc on line 172.

Re-editing reveals that the expiration date is not set.