Sandra Bullock blindsided by marriage woes?

The British premiere of Sandra Bullock's drama "The Blind Side," set for this Tuesday, will screen without its Oscar-winning star. Bullock pulled out Wednesday, citing "unforeseen personal reasons," according to a statement released by Warner Bros.

The cancellation, however, comes amid tabloid speculation that Bullock's marriage to motorcycle customizer/reality-TV star Jesse James is in trouble. The "Monster Garage" host allegedly has been involved with tattoo model Michelle "Bombshell" McGee.

James had been a fixture by his wife's side during the recent awards season, People magazine reports. He had nothing but kind words to say about her at the Oscars on March 7.

Bullock is "old-school Hollywood," James told People just after her win. "Nobody deserves this more and works harder. I'm so proud of her."

And Bullock appeared to feel the same way. When she accepted her Screen Actors Guild Award in January, she praised her normally shy husband for enduring the awards-show circus. "You get dressed up in monkey suits and you sit at a table with people you don't know," she said to James, adding "I love you so much, and you're really hot. And I want you so much."

However, in an interview with In Touch Weekly, McGee is claiming that James "gave me the impression they were separated." The San Diego model said the relationship began 11 months ago when Bullock was in Atlanta filming "The Blind Side" and McGee was seeking a modeling job with James' West Coast Choppers.

James has not commented on the allegation, but Us Weekly reports that he has canceled his Twitter account. The action raised eyebrows because James usually tweets daily.

Bullock and James have been married five years.

Photo: Michelle "Bombshell" McGee. (Credit: Facebook)