If you goto your "Item Watch" page and click the Delete option for multiple auctions without waiting for the page to reload each time, a bunch of empty auction entries appear in your list.
Just click Delete on as many auctions as you can before the page reloads, to reproduce.
A suggestion would be to add a checkbox to each auction, and allow multiple deletes at once.
Minor Auction Bug
Carinae
Dralspire
Thanks for letting me know.