The new adventures of Julia Louis-Dreyfus and Kari Lizer

BURBANK, Calif. – When you’re a working mother, you can’t always sweat the small stuff. At the end of every episode of “The New Adventures of Old Christine,” a black-and-white image flies by: “Kari’s Logo Here.”

Producers with big egos fine-tune their vanity logos to perfection. Kari Lizer decided to stick with the temporary filler that some technician had slipped in. “Come on, let’s not do this anymore,” she says she told the writers laboring to help her come up with something cute. “I have to get home and make spaghetti.”

Motherly duties rank just about even with employment for Lizer, creator and executive producer of “Christine,” and her star, Julia Louis-Dreyfus.

They are but one area of common ground for the two seemingly different women, one famous, one virtually unknown, who have found each other deep into their careers. (Lizer’s first movie role, in “Smokey Bites the Dust,” came in 1981; Louis-Dreyfus debuted on “Saturday Night Live” in 1982.) As a team, they seem perched on the verge of new, long-lasting success.

“The New Adventures of Old Christine” (Mondays at 9:30 p.m. EDT on CBS) is the season’s top-rated new sitcom (sorry, Earl), holding a healthy portion of the audience of the hit that precedes it, “Two and a Half Men.” With an average of nearly 13 million viewers, it is second only to “Men” (15.3 million) overall in the sitcom derby.

More important, though Lizer and Louis-Dreyfus are both in their mid-40s, “Old Christine” attracts younger viewers, snagging almost as many 18-to-49-year-olds, the advertisers’ Holy Grail, as “The Simpsons,” and more than such shows as “The Apprentice,” “The Amazing Race” and “Prison Break.”

“Yeah, how about that?” Louis-Dreyfus says in that distinctive low-pitched chirp that gives her diminutive person some of its comic clout.

We’re sitting in Lizer’s rec-room-size office in Building 136 on the vast Warner Bros. lot. Louis-Dreyfus, the big star, defers completely to Lizer, the boss, when the topic is the show. But when personal matters come up, the two interrupt or complete each other’s sentences as if they’re living almost the same lives.

The office is surprisingly neat. Most show-runners live in a playpen.

“We cleaned up,” Lizer says.

“We hired a team,” Louis-Dreyfus says. “You know, those cleaning services. It cost, like, 400 bucks, but it was worth it.”

“I’m pretty neat,” Lizer says. “Otherwise, I’d go crazy. My house sometimes feels like it’s going to explode … but I’m not a slob. I feel like I’m cleaning up every minute of my entire life, actually.”

“Yeah, really,” Louis-Dreyfus says. “That is so the truth.”

The mother role is crucial to both, a big part of the reason they are doing a traditional sitcom. It also helps explain how their show’s lead character, an offbeat gal constantly trying to do right by her school-age son, seems so relatable.

Lizer, in a “very civilized divorce” (like her creation, Christine), has 10-year-old twins, Annabel and Elias, and an 8-year-old son, Dayton. Louis-Dreyfus, married 19 years to former “SNL” costar Brad Hall (they met in college) is raising Henry, 13, and Charlie, 8.

Television dramas, with their punctilious set-ups, entail excruciating schedules, with workdays frequently running more than 12 hours. Sitcoms such as “My Name is Earl” or “Malcolm in the Middle,” filmed with the same single-camera technique, are somewhat easier, only because each show is half as long.

But traditional sitcoms have much more of a 9-to-5 rhythm. Actors see the script and rehearse without cameras as revisions are made for four days. On the fifth day, they perform before a live audience as four cameras shoot the action simultaneously from different perspectives. With persnickety producers, however, that can get dicey. “Friends,” for instance, was famous for plodding on almost to dawn as producers rewrote and re-shot scenes over and over.

You aren’t going to see that on “Old Christine.” They start at 5 p.m., not the standard 7 or 8. The latest they went in filming 13 episodes last fall was 9 p.m.

“We keep old-people hours,” Lizer says.

“A real early-bird special,” Louis-Dreyfus says.

“Our kids come to the filming more often than not,” Lizer says, “unless it’s inappropriate.”

“And they come most of the time then, too,” Louis-Dreyfus says, breaking into that strange, sucking laugh that was an Elaine trademark on “Seinfeld.”

Louis-Dreyfus appears to have conquered the so-called “Seinfeld” curse, in part, perhaps, because Andy Ackerman, who directed the last five years of that show, directs “Old Christine” and is an executive producer. Until now, none of “Seinfeld’s” supporting cast has had any sitcom success. “Watching Ellie,” Louis-Dreyfus’ first post-“Seinfeld” show, created by Hall, kicked around for a few episodes in 2002 and 2003.

“I had no interest in working right after ‘Seinfeld’ ended,” she says. “I had two young kids and I couldn’t really even imagine going back to work.”

Eventually, the bug reattached itself. “It’s exciting work. It’s very thrilling to make people laugh, and this is what I love to do. It’s just that basic.”

After “Smokey,” Lizer appeared in the infamous “Private School,” what she called a “teenploitation” film, starring Phoebe Cates, and a couple of other B movies. Then, she segued to TV, where she had recurring and guest roles for 10 years on shows from “Growing Pains” through “Matlock” and “Diagnosis Murder.” She moved into writing in a syndicated sci-fi comedy, “Weird Science.”

In 1994, she married journeyman actor Robert Romanus (Mike Damone in “Fast Times at Ridgemont High,” Snake Robinson in “The Facts of Life”), who guested in one episode of the show. For the last four years, she has been a writer-producer, and occasional actor, as Will’s secretary, Connie, on “Will ‘ Grace.”

Now, it’s good to be the boss.

“It’s the most fantastic job,” Lizer says. “It can be a real grind, but I’ve figured out where I’m actually creating and running the show, then I also get to set the tone for how it goes. I can get all my work done, and for the most part, go home and be with my kids for dinner.”

That spaghetti’s waiting.