TiVo reported a narrower loss in the fourth quarter on Monday as lower costs buoyed the bottom line in the face of a 20 percent drop in revenue. The Alviso, Calif.-based maker of digital video recorders with time-shifting technology lost $3.6 million, or 4 cents per share, compared to a loss of $6.4 million, or 6 cents, in the same quarter a year earlier.