I've been stuck in the Pits with the same thing once, re-assigned the clutch pedal on the options screen and all worked ok again. This was on a G29 but it should work.
yep just check that you dont have an extra thing assigned to the clutch or that if you have a clutch pedal its set up properly ; go into controls and re set your clutch pedal .... if your really stuck download DIVIEW to see if there is something bugging Andi