Lameness on the part of FOX, as per usual.
"The show was critically acclaimed, but did not gain a sizeable audience. According to the Nielsen Ratings system, U.S. ratings in the second season averaged about six million viewers, while the third season averaged about four million viewers. To promote their re-broadcast of the animated series Family Guy, FOX announced that it would halt the production of the second season at eighteen episodes – four episodes short of the planned season. Despite rumors that this was a prelude to cancellation, the network defended its actions, claiming that the show would fare poorly during network sweeps period, and that it was simply a procedural matter. For the third season, FOX positioned the show at 8:00 p.m. ET/PT and 7:00 p.m. CT/MT, directly opposite Monday Night Football in the Mountain and Pacific time zones, whereas MNF would not have started yet in the other two. Ratings were even worse than previous seasons. David Cross alluded to poor marketing of the show by FOX on the second season DVD. On November 9, 2005, FOX announced that the show would not be airing in November sweeps, and that they had cut the episode order for Season Three from 22 to 13. FOX ended up showing the last four episodes in a two-hour timeslot — directly opposite the opening ceremonies of the 2006 Winter Olympics, leading to poor ratings."