I'm aware the boxes I'm using have a cubic weight of a little over 5 kg domestically and a literal weight of a lot less, however after experimenting with 'International Shipping' the 'Package Dimesions' text boxes seem to disappear.  Either the intomation is still hidden somewhere I can't find it, or I need to set the weight to either actual weight, grossly under-estimating domestic ship or set weight to 5.1 and  (I have no idea) possibly grossly overestimate the international postage...  Pointers?