The famously troubled actor has been sober since 2001, and climbed to the top of the A-list  with this year's blockbuster Iron Man.

"Yes, he's postponed it," a Downey spokeswoman told E! News.

Downey's stellar work in movies such as Chaplin and Natural Born Killers was eclipsed in the '90s by drug busts and rehab failures.

On the right path lately, Robert is set to portray Sherlock Holmes on the big screen. And of course, he'll be strapping on the high-tech armor for the inevitable Iron Man sequel.

The memoir being shelved is a shame. The public is dying to know exactly how Burger King helped him kick drugs and booze.