"I knew I had a nice piece of arm candy on my arm," Bullock said at the Governor's Ball.
At the Golden Globes, Bullock told James from the stage, her voice cracking with emotion: "There's no surprise that my work got better when I met you. Because I never knew what it felt like for someone to have my back."
Things were different at the Academy Awards when the couple was last seen together publicly.
Bullock did not thank her husband, who appeared teary-eyed on camera as she accepted her award. Instead she thanked mothers and parents everywhere - including a poignant tribute to her own mother - along with her fellow nominees and "everyone who's shown me kindness when it wasn't fashionable."
Now, the couple is having to weather a very different type of media spotlight.
People.com is reporting Bullock left the couple's home several days ago, just before a report of infidelity by her husband surfaced.
Although he also calls the majority of allegations made against him "untrue and unfounded," James released a statement to People magazine issuing an apology to his wife.
"It's because of my poor judgment that I deserve everything bad that is coming my way," he said. "This has caused my wife and kids pain and embarrassment beyond comprehension and I am extremely saddened to have brought this on them."
Warner Brothers released the following statement from the Academy Award-winning actress:
"Due to unforeseen personal reasons a trip abroad to support 'The Blind Side' has been deemed impossible at this time. I apologize for any inconvenience this may have caused and thank you for your continued support of the film."
She and James were married in July 2005.
The Associated Press contributed to this report.