I am now sure that reloading wheel profile changes the behaviour of the control, I know this because the new Dirt update or the new windows update which in my case happened at the same time messed the controls. I loaded Dirt 2 and I noticed big big lag and too flat FFB. When I pressed the throttle it tooks 1 sec pressed full to put the revs up. I remembered the profile reload I did when I purchase the game, I did it and yep, the throttle now works as it did. Everything looked OK ingame, T500 was detected, and the control test page was perfect, but lag and flat FFB. Reloading profile fixed it. So try it if you have some strange wheel response, or just to try do it.