@David **********
well, i am not so sure. Thai imigration are known to change the rules of the game quite often. There are the "real rules" and the "unspoken rules". I myself experienced the troubles about getting my NON O visa extension. I understood they would not give me my renewal whatever i do, when they sent me back home for the fourth times because the pictures i was supposed to show didn't suit them for totally stupid reasons (need to wear long trousers, in the kitchen, on the sofa, show the house number, draw a map of the aera where the house is located (no you can't print Google map...) ect ect . DTV visa could very well be revoked or they can request any other dumb rule making it impossible to keep using it because they found this visa not suitable anymore for the country.