As for Sanook test websites, we will check them with the OpenX team in Tokyo.
At this moment, access from Japan to the links, there is no error what you found. Things seem to go well.
But when I (Akiko) access the links from Singapore, I see the same error "Invalid Domain Name" on the both links (Horo and Men) . I'm mainly using Chrome though.
So I reported these situation to our team and we will keep you posted.