Prob. of flush in 7 card stud with three-flush after 4th street?

[mdb]

In The Theory of poker on page 95, Sklansky says that there is 9-to-1 chance against making flush (spades) when you have a 3-flush (spades) after 4th street. In the example sited, there is only 1 opponent, and you see two of his exposed cards- both cards are not spades.

I am not sure why my math is incorrect.

I have {10/46 * 9/45 * 44/44) *3! = 26.1% - a very different result!!

Anyone know the correct math.