I am having this problem too....the worse case is one buyer from Queensland tried  to purchase my items (id 171466730057) last night and it keeps saying that she is in the location that I don't post to,  I am in Victoria and only ships within Australia. Then this morning she managed to buy one piece of one colour and tried to buy another colour from the same listing and it came up with the postage problem same as last night...until now she can't buy the second piece at all.... That is very strange as it is the same listing and it is very frustrating for me) :