there are more forms to fill in... But it's free. In bkk they didn't complain for me. But it was a different person who first did the movie, i think. Maybe the person who prescreened it. Then the new stamp was added.
Safest is to get a one year statement!. At least Bangkok bank will skip transactions in the bankobook if you have many, then they can't prove you didn't go below...
It takes 5 days to get the one year statement, needs to be ordered from the headoffice.