<<What happened in the movie anyway for it to come across as being racist?>>
Their were complaints that it portrayed an idyllic relationship between owner and slave (though the movie was set post-cival war), that it had historic inaccuracies that made the lot of a slave, or just a poor black person in the south at the time, not as bad as it was.
And then their's the complaints about the Bre'r Rabbit story. It has a Tar Baby...you can prob reason out people's complaints about that on your own.
Silly stuff really, imo, it's a nice lil movie. People are too damned worried about being politically correct. That movie was a product of it's time, and what people see in it as racist is really very minor compared to other things of the day. Look at old Bugs Bunny or Tom and Jerry...they were much worse, but you'll still see the offending episodes on TV on occasion.