Although I think intuitively I'd be inclined to agree, I took this from "Robert's Rules of Poker", which is probably the most cited set of Rules on the Internet. It Came from Chapter 3 - General Rules of Poker, under the Showdown section, point #1:

"1. To win any part of a pot, a player must show all of his cards faceup on the table, whether they were used in the final hand played or not. "

So, in remembering that the question is not who wins the pot, but instead, whether the SB has a requirement to show his cards in order to win the pot, doesn't the answer seem that he indeed does. I went through the whole set of rules and found nothing that contradicts this, and in fact there are instances where mucked cards can be retrieved so that the person who had mucked them can be declared the winner, so this would seem to lend more weight to the fact that the SB must show his cards.

If anyone can answer definitely it would be great, and again, thanks for those who have already responded.

Selena