The day of freedom has finally arrived!!
I believe I have fixed the problems with trading. You should now be able to change groups and sorting with no problems, in all modern browsers. Mobile SHOULD work too, although I haven't tested it a lot. Please let me know if you encounter any more trouble with trading.
EDIT: If you are still having trouble, clear your browser's cache! You don't need to delete history, cookies, or anything else. Also keep in mind that the site wasn't designed for mobile devices, so it may not always work. But I'll try to make it as smooth as I can.