sentences:  In 2005, Krens won a dispute with billionaire philanthropist Peter B. Lewis, chairman of the foundation's Board of Directors and the largest contributor to the foundation in its history.Lewis resigned from the Board, expressing opposition to Krens' plans for further global expansion of the Guggenheim museums.Also in 2005, Lisa Dennison, a longtime Guggenheim curator, was appointed director of the Solomon R. Guggenheim Museum in New York.