A few weeks ago I did not shut down my G3.5 properly. I'm not certain what I did wrong, but my guess is that I turned off the computer without closing G3.5 first. Ever since then the plane(I have checked this on 3-4 models) seems to be a foot or two off the ground. When I taxi slow from the runway to the grass the plane does not slow down when it hits the grass. It used to slow down and even stop when it hit grass and I knew to throttle up if I wanted to keep going. Anyone know what correction is needed? I'm sure that removing it and reinstalling it will correct the problem. I prefer to learn something from this.