When is racism not racism?

So Shilpa Shetty won Celebrity Big Brother - now there's a surprise! I would imagine most people who voted for her did so because of the way she was treated during the show, which was deemed by many to be racist, she being Indian. But this raises (for me at least) the question of whether voting for her for that reason alone would not be just as racist. You see my problem - if I do something nice for someone because they are black/brown/Jewish/Muslim/gay or whatever, then that's OK, but if I do something nasty to them for similar reasons then that's racist or homophobic or somesuch. If you're going to treat people differently for reasons such as those, then that I think is wrong, irrespective of whether you are treating them better or worse than you otherwise would. As George Bernard Shaw said, through the mouth of Professor Higgins in "Pygmalion" - "The great secret is not having bad manners or good manners or having any other particular sort of manners, but having the same manner for all human souls."