Here's the statement released by the United States Tennis Association a short time ago Thursday:
"We have faced an inordinate amount of rain in August and through the early part of September which has saturated the court surfaces at the USTA Billie Jean King National Tennis Center. All courts were completely dried prior to play on Thursday, September 8. However, as the sun began to warm, or 'bake' the courts, evaporation of these saturated conditions began to surface on Louis Armstrong Stadium. Until this situation is rectified, no further play will occur on Louis Armstrong Stadium."
That explains why Andy Roddick was moved to a smaller court with just 584 seats.