so i drove around last nite pretty late. streets were clear so i thought i would use my cruise control since i never did before. I was going about 35mph and i clicked it the green " cruise" showed up on the dash and i let go of the gas. then i noticed that it was slowly dropping like the cruise wasn't even on. And i was like screw it. I tried once more tonite. same results. I was on even grounds. Is 35 too slow for cruise control to work? What seems to be the problem?