I find it difficult to imagine that the reason for the ban is the one item listed. Certainly the first time I've heard of it. Every so often we hear of people innocently listing something that they did not know was banned on Ebay, and Ebay's action has been to pull the listing and warn the seller not to do it again. I've been there with a book I listed. So long as you don't do it again (however incomprehensible the item's ban is) there is no problem.