This is not a true "bug", simply XMM doesn't delete the previous directlinks you had inside the database, this because maybe you have import them with a chain.
- I don't use chains. But I'm importing a few movies at time - 10-20. - It's not about links only. Even if I click SKIP movie, script is executet in full, which means it's downloading all the data from imdb all over again. And it's also replacing all data (unless I set not to in the options).