JANUARY 13--You could excuse David Letterman for questioning CBS's commitment to his late night program. That's because the Tiffany Network actually opted for a prominent photo of Tonight Show host Jay Leno--instead of Dave--in its online promotion of Sunday night's People's Choice Awards. It wasn't until Letterman himself started ragging on CBS during the taping of last night's program that the image of his NBC rival was hastily deleted and replaced by a shot of the Late Show boss. Network brass apparently were so embarrassed by the gaffe that CBS president Leslie Moonves called Letterman during the Monday taping to apologize and say, apparently facetiously, that the employee responsible for posting Leno's photo on cbs.com had been fired. Below you'll find the before and after images from the network's web site, captured by TSG before the Leno art was deleted. While both Letterman and Leno were nominated in the favorite talk show host category, the People's Choice nod went to Oprah Winfrey. (1 page)