We have been running CS-Cart live for some months. Unfortunately we have seen that 90% of international orders are cancelled because of ridiculously high shipping costs calculated by the CS-Cart system.
The problem is this: most new customers will place a small order first. Small orders are light in weight and small in size. Shipping costs are low. But CS-Cart real time shipping costs malfunction, because it uses fake box dimensions and all carriers use dimensional weight.
Our customers complain heavily about the crazy shipping costs that cs-cart calculates, which can be €100 on a €20 order, which the real shipping costs are €10.
The problem with malfunctioning shipping costs are explained here: Why Dimensional Weight doesn't work in CS-Cart
There is already a request for dimensional weight in uservoice, but this was marked implemented without understanding what was requested by hundreds of people.
There isn't a real bug in CS-Cart because it works as designed. It just wasn't designed in a way that will calculate correct shipping costs. It will severely overcharge customers. As it does result in malfunctioning of the shipping cost calculation I have added it to the bug tracker here.
Unless CS-Cart fixes this issue, this may cause our website to fail. Which would be remarkable because our brick and mortar stores and other sites are highly successful.