Art auctions on both sides of the Atlantic this weekend broke existing sales records in some categories, but brought disappointment in others. A colored glass window by John La Farge fetched $242,000 at a Christie's auction in New York on Saturday, surpassing the previous record for an American glass window by more than $130,000, a spokesman said. The window, finely leaded and plated, was created by La Farge between 1893 and 1908. . . . In Paris on Friday, six world records were broken at France's most prestigious art sale in over a quarter of a century. The private collection of Impressionist works collected over 40 years by French businessman Georges Renand sold for more than $31.5 million, a record in France where high taxes have crippled art sales for a generation. But two paintings by Vincent Van Gogh, expected to steal the limelight after the $53.9 million sale of Van Gogh's "Irises" in New York earlier this month, were withdrawn from the sale for tax reasons.