You may have heard the news that 11 background actors ('extras') were injured on the set of Tom Cruise's controversial and beleaguered new World War II thriller, 'Valkyrie'. This was alleged to have happened when the side panel of a truck in which they were riding came loose as the vehicle turned. This coming on the heels of Jessica Simpson's suspicious 'broken nose' when she tripped and fell, shooting her new 'Private Benjamin' rip off 'Major Movie Star'. (Did she really accidentally break a bone or was she looking to justify a little rhinoplasty? Hmmmm.) Remember when Nicole Kidman and seven others were hurt filming the new box-office dud 'The Invasion'. There are certainly plenty of perils on movie sets for the stars as well as the stuntmen. This is one of the many reasons why it's so costly to finance the insurance on movie-making and especially for stars who are perceived to be liabilities, either because of health or behaviour.

Robert Downey Jr. had to prove he was recovered from his substance abuse woes by settling for work in low-budget independent films. Now he's back on the A-list, even telling his 'Iron Man' co-star Gwyneth Paltrow how excited he is to be starring in a movie that will attract a vast audience. This is what Lindsay Lohan is going to have to face if she intends to resume her star status on the big screen. Could she and her handlers be worried that it won't come to pass? Is that why they're looking on revisiting LiLo's musical aspirations as a 'Plan B'. Word on the street is that, even from rehab, plans are underway for her to deliver the third album she owes her label. Certainly the music industry knows how to handle problematic divas with more ease than the film biz. Mariah Carey, Britney Spears and even Madonna are good examples of pop superstars who couldn't launch successful big-screen careers (Justin Timberlake and Beyonce are still trying)while high-maintenance talents like Barbra Streisand and the late Judy Garland were better off playing concerts and making recordings than cause year-long headaches for movie producers. Then there are the Robbie Williams and Kylie Minogue types who should have been able to cross over to movie-star status, but public demand kept them pigeon-holed performing solely as 'themselves'.

Of course the biggest risk to being a movie star may not be the stunt work, backstabbing co-stars, location conditions or quality of craft services; it may be the fickle nature of the industry itself, with its ever-changing tastes and trends. There aren't many stars who have been able to maintain simultaneous box-office cache and clout. Here's my unofficial list of whom I consider to be the Top Ten leaders for reliability on both counts. Please add your thoughts and opinions!

1. Meryl Streep

2. Tom Cruise

3. Robert DeNiro

4. Mike Myers

5. Harrison Ford

6. Cameron Diaz

7. Will Smith

8. Tom Hanks

9. Adam Sandler

10. George Clooney