I'm having an issue with all my Reiza sims. I can't save or change my control settings because the sims all detect Joy3 Pup or something to that effect. when I try to enter a new control for my Logitech G27.
So when you try to program the keys, the game seems to think a button is already pressed.
Check your dpad on the shifter unit, and all other keys, and make sure there isn't one sticking down. (or shifter accidently in gear)
Or, do you have a couple of other controllers plugged in? It's possible that one of them is conflicting, it might be worth removing them and programming the G27 first, see if that clears the problem.
My problem with wheel settings is that every time I start the game, my custom control settings for my T500rs wheel is not displayed, instead, it is joystick control. That is not a big problem in itself; as I can just click through the different settings to my custom setting; the big problem is I often forget to do this.
If you are never going to use the other controllers, you could remove them all except your T500 file. Then it will be the only one to appear every time.
I do this for my G27, keeping two versions, a paddle and shifter version, everything else I delete.
Disclaimer: Delete files at your own risk, you might never need them, but it is best to cut and paste them somewhere safe rather than delete !