Call it the Paulie Walnuts factor.

For the first time in the nearly two months since The Sopranos new season began, viewers are flocking back to the show.

Ratings for the mob opera have been on a steady downhill slide -- off by nearly 28 percent since its September premiere -- until last Sunday when Paulie "Walnuts" Gaultieri (played Tony Sirico) returned as a major character on the show.

In the hit series, Paulie -- one of the show's most volatile and violent characters -- has been stuck in jail on a gun charge.

Now that he's back on the streets, viewers apparently are expecting the show -- which has been roundly criticized this year for its meandering plot course and slow pace -- to pick up some speed.

Fans have been waiting for someone to get whacked on the series -- and Paulie's return promises a return to the show's gangster-story roots.

Before Paulie's release from jail, the show had its lowest rated episode of the season -- about 9.7 million viewers, significantly less than the 13.4 million who tuned in when the show returned last September.

This week, the ratings shot up to nearly 11 million viewers.

Fans have been complaining bitterly that the series has lost its way this year -- ignoring promising plot lines like Uncle Junior's racketeering trial in favor of Tony's less-that-riveting romances.

Over the course of The Sopranos four seasons, Paulie Walnuts has emerged as one of the most charismatic characters on the show, despite the fact the he's a cold-blooded killer.

He played a major role in last year's critically acclaimed episode that took place in New Jersey's Pine Barrens -- an episode that many fans feel turned Sirico into a star.

And this season, even while locked away in prison, Paulie was able to stir the pot enough to nearly start a gang war between Tony Soprano's Jersey-based gang and his rival bosses in New York.

Still, not everyone attributes the ratings bump to Paulie.

"Stranger things have happened, but I don't see it," says TV Guide's Lois Draegin, who edited a best-selling special issue on the series last fall.

"I never knew there was such a ground swell of adulation for Paulie Walnuts, as great and wacky a character as he is," she says.

"I can't believe it's due to him," says WABC radio talk show host and Sopranos aficionado, Mark Simone.

"I think it's because this was the first Sunday night of the season when the show really didn't have any major competition-like the World Series," Simone says.

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