I forgot to mention that the Thai Immigration Officer gave me a small pink paper with the date. It stated that if you stay more than 90 days in Thailand, you need to go nearest immigration office to report or do it online. It is to confirm the location of your stay. If you stay less than 90 days in Thailand, you don't need to report.
I travelled to many countries and returned to Bangkok. All check-in counters never asked me for proof of visa because my passport allows me to travel to 177 countries without a visa.
Did not you read my message? I just applied for a DTV visa today and am waiting for approval tomorrow. Then I shall try at the border. I have heard that many non-immigrants visa have confronted this issue at Poipet, but I have never experienced it.