My gearbox has suddenly got a problem!!! It has been fine and was OK when I put the car in the garage yesterday. Today when I tried to reverse out the car would not move and the engine stalled. I tried again and found the gearbox appeared to be locked. I put it in neutral and started to release the clutch and it started going forward. I tried to select 1st, 2nd, 3rd and 4th but I couldn't get the gear lever to move to any of those gears. From neutral it wouldn't even go across to the 1/2 position. Feels fine going between 5/R. Does this sound repairable?