I've got to get a new pump. I use Maxxis Locust CX, and last Sunday at Alpenrose, I rode them at a pressure my pump told me was about 35 psi. No problems, and I weigh 185. For Wednesday, I was expecting rougher terrain, like last week, so I pumped them up to 40 psi, but that felt to firm, so I let a bit more air out. Again, no problems.
My cheap (Hurricane Essential) pump's gauge must just be miscalibrated. Either that or I need to ride harder. Maybe both.