NBC's Monday night Malcolm in the Middle rip-off, Tucker, has become the first casualty of the 2000-01 fall TV season. The network has cancelled the low-rated, critically reviled sitcom and put its lead-in, Daddio, on hiatus. The 8 pm hole will temporarily be filled by another edition of Dateline NBC. The news wasn't all bad for The Peacock: Despite losing to ABC in total viewers, NBC came out on top last week among adults 18-49. Meanwhile, the premiere of David E. Kelley's Fox drama, Boston Public, got off to a strong start Monday night, winning its timeslot in total viewers (13.9 million) and in most key demos. The return of Ally McBeal netted 13.2 million viewers, down 17% from last season's premiere.