I know exactly which belt buckle you are referring to (or pretty sure I do) and I know that type of belt you are talking about. The answer, in short, is that the maker of the buckle makes them backwards from the standard belt (presumably in an effort to ensure that you buy his belt as well. Typically, a buckle will attack the the right hand side of the belt and fasten on the left (as you wear it). The only easy solution to your problem is to get a belt that is the same upside down or right side up like one of the Celtic knotwork belts.