I just know someone in Pattaya immigration fined 1.600 about lacking of registration, normally should be owner house to pay fine, anyway if owner don't pay immigration refuse every service to foregneir. so he forced to pay in advance and ask money back owner house. Staff immigration also say if you leave country and you did not have this form you can be asked to pay 5.000 baht in airport, but I really don't know anyone had this kind of problem.