never mind - found the issue. global product detail setting had inventory turned off.
Does anyone know if it's possible to customize the error message that displays when someone tries to order an invalid quantity on a per-product basis? IOW - if I have a specific product configured with a max # of units that can be ordered - can we customize the error for just that product?
Also - can a rule be implemented that prevents a single user from ordering more than N units ever? IOW prevent the same user from submitting subsequent orders with the max # of units on each order...?