The same thing happened to me. What it is is the course itself is changing. There are courses that are more trafficked than other people. If your course is getting more traffic those other guys shouldn't be playing multiple discs. It sucks when there are tons of people on the course. The answer for me was to drive an extra ten minutes to a newer course with less people. If your course is trafficked someone will start to tell those people off.
Psychology and Technique