 Shares of Ciena Corp. CIEN, -1.86 tumbled 11.3 in premarket trading Thursday, after the networking systems company missed fiscal third-quarter profit and sales, as component supply issues which hurt deliveries offset strong customer demand. Net income for the quarter to July 30 dropped to 10.5 million, or 7 cents a share, from 238.2 million, or 1.52 a share, in the year-ago period. 