I'm not sure this has anything to do with geography, I think it's a bug in their systems that puts SIN in N Asia for no good reason (which they seem happy to overrule if you point it out). But it's one that you can use to your advantage. Each time I call the initial quote I get makes it clear that they are including Singapore in N Asia. Since I am starting in Singapore, there are a bunch of awards that are better valued when SIN is considered N Asia so I dont bother to argue for those. To take advantage of the great deals within the S/Central Asia grouping, I just mention that they must have made an error because Singapore is actually located directly south of several countries that are in S/C Asia. They usually do some tapping and come back saying I am right and change the # of miles. Maybe next time I will book SIN-LAX and tell them that Singapore is actually located within the US, maybe they are so geographically challenged that they will go for that!!

Other than having to pay a family member to fedex the paper tix across the pacific to me, I love my US miles over here!