That means you need a bigger/wider tire for your weight. On the BROL Forum this was discussed a great deal, and that going to a wider or narrower tire, you can get to a point where you have the correct cross-section at max PSI, or at minimum PSI.
In this case, you would gain speed by going to either a higher pressure tire in the same width, or a better ride by going to a wider tire. No matter what, the current tire is *not* the best choice for you. I went to a max PSI of 65 on a marathon 26 X 2.00 on my Suede DX to get the best cross-section at the max PSI.