The book publisher for Maureen McCormick, who played Marcia Brady on the 1970s sitcom "The Brady Bunch," is shooting down rumors that she had a lesbian on-set affair with co-star Eve Plumb, who played her younger sister Jan.........[A href="vny!://abcnews.go.com/Entertainment/story?id=3638969&page=1"]vny!://abcnews.go.com/Entertainment/story?id=3638969&page=1[/A]