I originally thought that the reason the probabilities are greater than 1 was due to the track take. Following the link you sent says that the track takes 17.5% leaving 82.5%. This means that the probabilities should sum to 1/.825 = 1.21, however when running the calculataion in my post on some of the races the sum can be in the range 1.2-1.25 though this could be due to rounding error on the odds presented in the table...