Bernie
Afair you are using a G25?
If so try to reinstall the Logitech gaming software "lgs510.exe", in W7 it must be resident in tray bar.
But shifting problems can be caused by a little switch being worn out...
I retired my G25 because of lots of double downshifting!
May not be relevent in your case, but now & again, I find my wheel slowly turns to the right when I jump in the car. Re-calibrating within GPL doesn't seem to help, but if I exit
the game back to desktop, unplug wheel/reconnect wheel, all seems better for a while.
While you are also talking shifters...
I had issues with my replacement G25 shifter [Logitech had previously sent me an entire new setup under warranty due to misbehaving shifter]. I've fairly recently obtained a G27 shifter from Logitech online spares shop [about £30 or so] & hooked it up directly to USB port via a Bodnar cable.
Cheers,
Dave.