As soon as a trade gets accepted the cards you are expected to send should not be available for any other trades as they are already committed, and the cards you are going to receive should not be in your wants any more either. This prevents other people from getting matches for cards that are already committed to a trade and sending trade offers that are not really viable.
We are now managing your card lists in this way. Your lists get updated as soon as a Tracked Trade gets accepted, to prevent any confusions or double trades for the same card. And the lists get restored if the Trade expires before you send or receive.
We hope this will further improve the usefulness of our Tracked Trades system. Please let us know if you notice any issues.