I'm having the same problem. Made a model and printed to pdf files at a size to fit onto 8 1/2 x 11 and I have these 5 MB pdf files, which, by the way, I notice redraw including ALL of the data in the model, including objects that I cannot see in that particular view. Maybe that has something to do with it? The reduce file size function in Acrobat isn't taking care of it. Thanks.