The best thing to do is check out a store that sells the same type of fixture and see if it shows the same sign. If it doesn't then there must be something wrong. Also, you can consult a store staff about this because they should be able to offer you some useful info about it. :)

Here's a link to some info and pictures, also treatment. Here is a link that might be useful: link

I agree, it's going to irritate you, so I'd take it back. I cook in non-enameled cast iron regularly, it keeps my iron level up according to my old doc, and the flavor doesn't bother me. I can't imagine that such a small flaw would actually affect the flavor of what is cooked in it, but you'll always be wondering if MAAAYYYBBBEEEE that's iron you taste. I also know that enameled cast iron is expensive, so I would take it back if I thought I would be unhappy with the condition, no matter how minute the spot. Annie However, I know that enameled cast iron is expensive and

What color & how big are the spots? Can you post a pic?