I am currently in-country in KutRang... I already registered my wife's house and was trying to use the government site [members only]/ to do my TM 30 check in. Well, that site flatly refused to accept my data. I had used it before, but this time no go. I think something perhaps that it required an arrival number, but they no longer issue those. Anyhow... a couple of google searches and I found [members only]/ which gives 4-5 free registrations. I provided my current creds to the thai immigration site, uploaded my passport picture and about 30 seconds later was finally checked in. Perfect!