Jay Leno’s 10 o’clock show was supposed to revolutionize prime time. But sometimes revolutions leave destruction in their paths.

In the first two weeks of the new TV season, the ratings for NBC’s prime-time lineup are down every night of the week except Sunday, when the network airs National League Football games (and not Leno). Trauma and Mercy, NBC’s two new dramas, have struggled to get sampling. Law & Order: SVU has lost a third of its 18–49 audience since moving to Wednesdays at 9 (it aired at 10pm for six seasons). The critically praised cop drama Southland, conceived as a 10pm show, was canceled before it could even start its second season, which was supposed to begin October 23 at 9. The Tonight Show With Conan O'Brien has lost its substantial lead over Late Show With David Letterman among viewers ages 18–49, the category most important to advertisers. And after a strong start in Leno’s first week, ratings for the NBC affiliates’ local newscasts have declined year-to-year since September 21.

The Jay Leno Show has also brought an older audience to the network, which has always insisted that it only cares about reaching the 18–49 demo. The median age of the network’s audience has jumped by 2.7 years to 48.4 this season, due in large part to Leno. Viewers of ABC and CBS have also increased in age, but not nearly as much, and Fox has actually gotten younger.

Overall, Leno has settled in at around 5 to 6 million viewers and a rating of 1.5 to 2.0 among 18-to-49-year-olds. NBC Universal Entertainment chairman Jeff Gaspin tells TV Guide Magazine the show is working from a financial standpoint, as it’s not nearly as expensive to make as a scripted drama. “Leno made smart business sense for us,” he says. “We’re still doing fine in that regard.”

But Gaspin acknowledges that the network is going through a period of adjustment as shows have been displaced by Leno, especially Law & Order: SVU, which dominated its time period in recent years on Tuesdays at 10. It’s now in fourth place, competing with CBS’ potent Criminal Minds. “There was more risk than we expected by moving some of our 10 o’clock shows to earlier time slots,” says Gaspin. “I think many SVU viewers and fans will find it at 9 o’clock and the ratings will slowly increase over the course of the year. It takes a little longer than it used to.” As for the performance of the network’s new shows, “We need to learn a little patience,” he says.

Gaspin believes the 10pm gambit will make sense over the course of the season, especially when CBS and ABC are in repeats and Leno is airing original episodes. (Leno has already topped ABC on some nights.) Ratings success at 10pm has also gotten tougher as more viewers watch shows on their digital video recorders in the hour. Gaspin maintains that if NBC can remain profitable with Leno at 10, the network can focus on developing stronger shows for earlier in the night. “The bigger issue is our 8-to-10 block leading into Leno,” he says.

As for late night, the belief inside NBC is that Letterman’s lead over O’Brien has more to do with the tsunami of publicity surrounding the CBS host’s revelation that he was blackmailed over having sex with staffers. Insiders believe if the details get more sordid, female viewers could eventually abandon Dave.

But NBC has to address the quality of Leno’s show. Network research analysts say there is heavy tune-out during the commercial breaks. Even one of NBC’s own employees, MSNBC’s Morning Joe host Joe Scarborough, excoriated the program. “When they do one of those skits in the middle of the show with the young comedians, they should just put up a neon sign that flashes change your channel now,” he said. “They are horrific.”

Gaspin contends the network is happy overall with Leno’s show, but it’s still a work in progress. “Has everything worked? No. But I think this is the show we wanted, and it’s the show Jay Leno always intended to put on,” he says. “There are things that need to be tweaked. I think they’d be the first to tell you that. Part of the problem is that there was so much hype leading up to this that people expected the opening of the Olympics. That’s not what the show is. It’s a daily talk-variety show, and that’s what they’re producing.”