Quicksilver: Wishlist displays wrong number of items

Description

Steps to reproduce:

1. Login to Quicksilver sample site.
2. Add "Faded Glory Mens Canvas Twin Gore Slip-On Shoe" size 7 to wishlist.
3. Add "Faded Glory Mens Canvas Twin Gore Slip-On Shoe" size 8 to wishlist.
4. Click on MiniWishlist, update "Faded Glory Mens Canvas Twin Gore Slip-On Shoe" size 7 to size 8.
5. Go to Wishlist => Observe there is 1 item "Faded Glory Mens Canvas Twin Gore Slip-On Shoe" size 8.

Expected: Wishlist 1 item.
Actual: Wishlist shows 2 items.

Note: If we add another item to the wishlist, actual is 2 items but wishlist shows 3 items.