That's why I said it doesn't seem to... But last time I left the country I had one day overstay, when I paid that they told me that it was no problem because I never over staid before, but I had about a week over stay a couple of years ago.
I have seen the stamp before, and I really don't know about the people I met, I didn't see their passport, except a girl from China that did not have a red stamp. She had four back to back visa.
The two last time I went to Vientiane I saw a lot of people that was denied a third or more back to back visa. Mostly Asian people, but I also talked with Americans, Dutch, French and German that was denied.