A constant and consistent barrage of blown deadlines are what ultimately finished Aaron Sorkin's (search) four-year tenure as the behind-the-scenes brains of The West Wing.

"There were financial issues and creative issues," a West Wing source said.

Sorkin, who created, executive-produced and wrote almost every single episode of the critically acclaimed White House drama had been under increasing pressure from Warner Bros., the studio that produces the show to get his scripts in on time.

"There were times when the actors where sitting around with no script and getting paid for it," a source said.

Sorkin, co-executive producer Thomas Schlamme and the show "amicably" parted ways last week. Executive producer John Wells -- who also oversees ER and Third Watch -- is now in charge.

Behind the scenes, Sorkin and Wells are said to have participated in an increasingly contentious series of meetings and conference calls with Warner Bros. brass who were angry at Sorkin's tardiness, industry sources say.

"There were conversations were it was said that 'businesses can't be run this way,'" an insider said.

"Those blown deadlines ended up costing the studio millions and wreaked havoc on the schedules on the cast and crew," the insider told The New York Post.

As the pressure mounted, Sorkin -- who has famously battled drug abuse -- wanted out. In 2002, during an appearance on the Today show Sorkin even said he planned to leave the West Wing in about a year.

"The late delivery of scripts was hard on production and brought the show in way over budget," a studio source said. "It's just hard all the way around on everyone and they were way, way over budget because of it."

But Sorkin, "likes to do the show the way he likes to do it and probably decided 'I'm gonna go out this year and that'll be it," a source close to the producer said.

Sorkin could not be reached for comment.

Meanwhile, Sorkin's exit is said to be bittersweet for the cast who loved and respected the producer, but sometimes were hard pressed to memorize pages of the show's trademark, tricky dialogue in record time.

Warner Bros. officials did not return calls for comment.

The administration change on West Wing comes less than a month after reports surfaced that Warner Bros. had put Sorkin on notice and warned that it would no longer tolerate cost overruns due in part to Sorkin's habit of delivering scripts late.

Sorkin's fall from grace with Warner Bros. is just latest chapter of woe for a group of powerful writer/producers who rose to fame in the late 1990s.

David E. Kelley, who was once considered one of the gifted in the business could be facing the series finale of his long-running show The Practice tonight. ABC might dump the show from its schedule later this month.

With the exception of Boston Public, other Kelley shows haven't fared well either in recent years. Snoops, girls club and Chicago Hope have all been canceled.