Like many art lovers, Dianne Stohler is addicted to Van Gogh. Unfortunately, the master artist has indirectly caused her a great deal of financial anguish - a market loss of about $72,000 on her Sotheby's shares. Much of that loss occurred last month in response to Sotheby's disappointing auction of Impressionist and Modern paintings led by a Van Gogh masterpiece, "The Fields," which the artist ...