I use AOS and the client version 4.whatever from that link up there. My trading gump has some problems too, but I wouldn't call it broken.
I can trade one item at a time, and if another person trades with me, all I can do is click the ok check. I cannot drop anything into my side. If I start a trade, I can only drop one item in there.
It's rare that I do all that much trading, so it's not what I'd call a big deal. Plus, we're dealing with WODians here, and if I can't trust them to live up to the terms of a simple trade, then I have more serious problems than my trading gump.