There's a well known scam here for starters.
http://www.andrew-drummond.com/2009/06/28/809/The moral of the story, keep out of the bangkok airport shops.
There's a lot of other stuff which I can't find right now. It is well know that they won the airport contract because they where pals with Thaksin, who was overseeing the new airport whilst making his bank account fatter.
To be fair, they are just one of many corrupt Thai organisations. They just have the bigger bankroll over the competition.