While we were there in October, there were several "walls " of plastic hanging in attempt to keep the dust from the renovations (construction) getting everywhere.
Perhaps that contributed to the lack of ventilation and the smell of stale cigarettes. The Casino was not crowded, but the smell was pretty strong. Of course we didn't win either, but we went there for the entertainment, and knew we probably would not be winning enough to pay for our next trip to SXM.