interfaceone is usually very good with these things..
Fanatec shifter works fine.. so the wheels o.k.
all three lights are on.
So you know your getting power, the board can see the wheel and the board can see the shifter.. connections are probably good.
so that leaves two possibilities.
The boards faulty, or the shifters faulty in some form!
since the board reads USB codes and output's voltages.
testing the board in sequential mode might help determine if the codes running on the board.
but doesn't help with eliminating the functionality of the H mode switch.
have you tested in sequential mode?
Does the problem only show up on Dirt3? how about GT5?
Shifter testing..
Do you have a PC?
Can you plug the shifter into it, and load the driver software and confirm that the shifter is working O.K. via the controller properties page.. or better still reset the shifter to factory settings via a PC, cause the shifters programmable!
It's probably possible to map every gear as reverse and store it in the shifter!! or map seventh gear to sixth
Other Ideas:
With the shifters in H mode and in neutral the shifter could look like it's in reverse if the shifter thought it was in actually in sequential mode (faulty shifter switch?) but I'm guessing you've tried using it with the interface board in sequential mode?
If it looks o.k. on a PC..
Then it's possible it's a faulty board.
hopefully this might help in some way, good luck and let us know when you get it working.
Cheers
GSL