I have a  Fanatec Speedster 2 steering wheel however the accelerator  pedal does not allow cars to go forward even though I can use the pedal to confirm choices when navigating the menu.
I have tried it with Need for Speed Underground and Need for Speed Most Wanted.
The button on the steering wheel which is assigned for acceleration - does work to confirm options within the menu but not to accelerate cars.
Anyone encountered similar problems ?

Hi. 
 
I also have a Fanatec Speedster 2 but I didn't use it for some time now. When i got to play with it, i found the same problem as you, but with the brake pedal, which it doesn't respond.
 
The acceleration pedal works, even for confirmation in games menu. In Gran Turismo 3 none of the pedals were working but in the rest of my racing games only the brake didn't work. I tried every option possible but with no luck =\ 
 
As your question was 2 months i wished to ask you if you had found any solution to your problem, since we have similar ones. 
 
thank you for your time ;)