LOS ANGELES -- Britney Spears’ big "surprise" may not be such a shocker after all.

NYDailynews.com reports that the rumors are true: Spears will perform on the MTV Video Music Awards Sept. 9 in Las Vegas. The Web site quotes a source close to Spears’ manager as saying her record label is worried that any missteps or a no-show at the VMAs could hurt her comeback.

Meantime, a Los Angeles court commissioner said he would consider unsealing documents in the Spears-Kevin Federline divorce case. Federline’s attorney said the documents contain information about the schedules of the couple's children and other details that could put them in jeopardy.

"It would be best for the children that they not be exposed," Mark Kaplan said. He gave no specific examples of threats to the children. Spears attorney did not talk with reporters after the hearing.

Since February, Spears, 25, and Federline, 29, have shared joint custody of their sons, 22-month-old Sean Preston and 10-month-old Jayden James.

Federline’s attorney said K-Fed is seeking additional custody because the two boys are "isolated from risks" when they are with his client.

Two more hearings in the case are set for mid-September.