Stagecoach Sleepiness

This semester, I'm working for my old professor as a teacher's assistant and it's a fun and easy job. All I have to do is basically show up on Monday and Wednesday mornings, pop the movie in and make sure that nothing goes wrong with the projector. The films, for the most part, haven't changed too much since I took the class (he did add The Hours, though, which led me to a major re-evaluation of that film) but it's hard to go wrong seeing Citizen Kane, Boogie Nights and The Graduate again. Tomorrow, however, I have a slight problem. As a part of western week, the professor is showing Stagecoach as an example of the "classic" western. I've watched the film twice now-- the first time was actually the first movie I ever saw on TCM and the second was in this class when I took it-- and I'm surprisingly positive towards it concerning my feelings for John Ford films most of the time. The only problem is this: both times I've watched the film, I've fallen asleep in the exact same place and then waken up in the same place about 30 seconds before the ending. Seriously. I'm good right up until the stagecoach reaches their destination but then I have no recollection between then and the climactic shootout between John Wayne and the bad guy. Maybe tomorrow will go better, but I'm not holding my breath.