I have a question about commerce. When I enter a discount coupon based on a fixed discount price, the checkout always triggers the shipping step with the default shipping option (the product has a different shipping method, which is not shown in the checkout because it’s not necessary; this is also configured that way—digital product). I notice that when a discount is applied based on a percentage, suddenly the shipping step is no longer applicable. Do I need to configure something, or is this a (known) bug?
FYI: The shop was still running under 1.4 I updated to the latest version 1.6. In 1.6 this sideeffect was solved 
Thanks @markh for the helpfull feedback.