I have just installed the Smith Cart (DNN5) and gone through the basic setup, creating both the store page installing the Smith.BuyNow module and the product detail  page and installed the Smith.ProductDetail module.

I  can add a new item to the cart, but if I try to click the product name to call up the product detail I get a critical error on the product detail page. 

The error is A critical error has occurred.
Can't get ModuleId for given module name 'Smith.BuyNow'

Any idea what I have overlooked?