IMAGE SOURCE: Brocade Communications Systems.What: Shares of Brocade Communications Systems (NASDAQ: BRCD) fell 11.5% Monday after the company issued disappointing preliminary quarterly results.So what: For its fiscal second quarter ended April 30, Brocade now anticipates revenue to be in the range of $518 million to $528 million, down from its previous outlook for revenue of $542 million to $562 million.