Depends on your definition of racism.
SotS's problematic elements are not overt explicit stuff like you'd see in The Birth of a Nation, just more the result of naivety. Blogger Unshaved Mouse thinks the film would be a lot less controversial if the film were called "The Tales of Uncle Remus" or something like that, because that's all the film is. It's just a kid hearing stories from this old man, nothing more.
But the actual title makes it seem like the film is saying that this is what the south was like, and since the film never acknowledges slavery or anything like that, it seems like they're whitewashing history. Not harmful for kids, but problematic for anyone who knows a lot about history.