I used to have a list of users with whom I had matches in my wishlist or tradelist on the main page, and now all of a sudden that has disappeared and I can't seem to find any trading partners anymore.

Hello,

We've written a little bit on this issue in this announcements post: http://deckbox.org/forum/viewtopic.php?id=1461] towards the end.

The gist of it is that the widget had some performance and usability issues, and it will come back in the near future, redesigned.