I'm at work so I don't have my Missal in front of me to reference.
In the High Mass, when the people are incensed we stand. The New Roman Missal (Fr. Lascance, 1945) instructs us to remain standing for the Preface. I take this to mean that we stand for the incensing and do not sit down. What happens at the Church I attend (Motu Mass) is that the people stand for the incensing, sit afterward, and then stand for the Preface. I am always the only one standing throughout that part.
Am I mistaken?