That sounds like a lot for a bike the size and weight of the BA unless you're a real big guy or are riding two-up much of the time. I run about 36-38 lbs in the rear on my bike but I still have to stock Bridgestone. The stock rear suspension on these bikes isn't very compliant to start with and I feel running a little lower pressure keeps it from being too harsh on my back. The higher pressure should keep the tire from heating up as much and make it last longer. Of course, 12k bone jarring miles at 40 lbs as opposed to 10k comfortable miles at 36 lbs may not be worth it.

Experiment with the pressure a little and see what works best for you. My understanding is one way to tell if you are running about the right pressure is to measure it with the tires cold then ride for an hour or so and measure it with the tires hot. The difference should be about 10-12% (so 35 cold should give you about 39 hot). If the change is much greater than that you are probably running too low a pressure and should increase it.

Keith