Anytime I come to a complete stop using the wheel controls for a g25 i cannot accelerate again, even though if I switch to KB/mouse controls I can. Does anyone know how I can fix this problem?

Odd, but as a complete guess, i'd say you've either stalled, the engines switched itself off or you've run out of petrol. I think switching to KB/mouse will restart the engine when you jump back in.

I've tried going like 5 feet, then stopping. Same problem.

Check your clutch settings. What car is it?

It may be that it is stalling because the clutch isn't coming in. Can you hear the engine idling?

I had this exact problem, found that due to me being slightly overkeen and frequently pulling my wheel from the table I had slightly disconnected a lead underneath my G25.

I know this sounds a bit obvious to check but it was my problem.

I'd hazard a guess that the engine stalled. Go into options and set a button for "Ignition". Then push that button when it "stops working" again.

Also don't forget to push the clutch in when starting the engine. Just like IRL.