Warren Buffett biographer Alice Schroeder's all-access pass to the Oracle of Omaha has been revoked, it seems.

Schroeder said Buffett told her a month ago he would not attend a dinner she has hosted since 1998 on the eve of

Berkshire Hathaway's

annual meeting in Omaha each spring, according to the

Associated Press

.

"We've had very little contact since the book has been published. A few e-mails, and that's it," Schroeder told the AP in an interview on Wednesday, suggesting their relationship has cooled since the publication of her best-seller

"The Snowball: Warren Buffett and the Business of Life."

Buffett cooperated with Schroeder for five years for the writing of the book, and reviewed it prior to publication in September 2008.

Schroeder, who once covered Berkshire as an insurance analyst, discussed the book on

TheStreet.comTV

.

Buffett assistant Debbie Bosanek said the cancellation of the dinner event was not related to his opinion of the book, according to the AP.

"Mr. Buffett likes Alice, likes her book and has received a number of glowing letters from friends about it," Bosanek said. "But at some point, like the charity golf outing he once hosted, an event runs its course."

While Schroeder said she has not heard anything directly from Buffett about her book since its publication, she acknowledged others have told her Buffett was troubled by sections dealing with his personal life, notably the chapters on his first wife, Susan. Susan Buffett left Omaha in 1977 and moved to San Francisco. The couple never divorced before her death in 2004, despite the fact that Buffett was living with his longtime companion, Astrid Menks, most of those years. Buffett married Menks on his 76th birthday in 2006.

"We're not at war with each other, but he's distancing himself from me," Schroeder told the AP.

Schroeder said she still plans to attend this year's Berkshire shareholders meeting on May 2, where tens of thousands come to hear Buffett and Berkshire Vice Chairman Charlie Munger discuss their investments in holdings like

American Express

(AXP) - Get Report

,

Wells Fargo

(WFC) - Get Report

and

Coca-Cola

(KO) - Get Report

.

This year's event will hold extra significance as a number of Wall Street pros have been publicly wondering whether Buffett has lost his magic touch after his investments in

General Electric

(GE) - Get Report

and

Goldman Sachs

(GS) - Get Report

have soured since last summer.

RealMoney.com contributor Doug Kass recently published an article discussing "

the potholes

" in Berkshire's investment portfolio and the sharp drop in market value in some of Buffett's largest holdings.

Before joining TheStreet.com, Gregg Greenberg was a writer and segment producer for CNBC's Closing Bell. He previously worked at FleetBoston and Lehman Brothers in their Private Client Services divisions, covering high net-worth individuals and midsize hedge funds. Greenberg attended New York University's School of Business and Economic Reporting. He also has an M.B.A. from Cornell University's Johnson School of Business, and a B.A. in history from Amherst College.