It's a common tactic from the Chinese and Russians to get past blocks by changing their primary address to one in a country you will post to. They then change back to their ordinary address.

I once agreed to sell to someone in the US but my blocks were in place even though I'd exempted them personally, so they couldn't pay on the invoice. They really wanted the item so they paid me direct through paypal. I didn't understand how it all worked so I stewed over for it a while and thought I'd lose my $130 but afterwards I understood it better.