Another Celeb Paradox

So, because I can't ever remember that I don't have to watch commercials, I never stop the TiVo (I know, it's not really a TiVo, but I want it to be) and always see the ads. There was just an ad promoting the Dukes of Hazzard movie, availble on HD...fine, whatever. But, I don't understand how Jessica Simpson, who is FROM TEXAS, can't do a southern accent. How is that possible? You are from there. In the ad she sounds like a brit trying to do a texan. She IS texan. What the hell? No wonder the one true love of the century failed.
I miss the snow.