Can someone who knows about Ikea beds please tell me what the deal is with using box springs with them? Is it an option, or do you have to use the slatted platform thing? Does it make the bed way too tall if you do use them?

If you missed it in the Bargains forum, they're having a huge sale on a 3 pc set this Saturday, but I'm trying to figure out what I'd do with the boxspring if it wouldn't fit in the bed.