You'd better have a clean passport and hope that whoever is in charge that day is in a good mood. I had a single visa exempt stamp and I asked if I could get a tourist visa instead since they couldn't give me the ED visa. They told me (and the group of people I went to the consulate with) to get it in my own country. On my way out, another staff member told me to try again the next day. Went back to Bangkok on my second visa exempt stamp and got questioned for about half an hour and received a lecture about why I should have gotten a visa before coming back. My mother was supposed to come here and travel to the north with me, but BOOM! Because she had a tourist visa (a single one) from earlier this year, the officer at Suvarnabhumi denied her entry and forced her to buy a ticket back to the States instead of stamping her in for 30 days.

Because they said they would have to reapply at the ministry of education, which would take 3-4 weeks again.

Is it possible to bring your ED visa documents, ask them to look at it first, and if something is wrong, tell you straight up, so you can apply for a tourist visa instead (to give you time to get the new docs)? Or do they just get the paperwork and you get a surprise the next day?

The thing is, we were told this was happening in Vientiane and Savannakhet. That's why we were advised to go to HCMC. Just last week, I saw a post from someone here who didn't have any issues there.