I'm not sure if this is only a problem with the Mournhold traders, or if I'm just lucky enough to only see it there, but three times now I have done various searches (a feature which I LOVE, btw) and had problems with the interface. Sometimes, it simply goes blank and freezes the game, forcing a reboot. Sometimes, it goes blank and I can move from trader to trader, but it's blank everywhere. The screen comes up, but with no content and no options except to back out. If this happens, it sticks to any trader I try to visit in any city.
Last night, it somehow arbitrarily decided I was sorting by unit cost and was throwing an error stating that there were no matches that contained both my item and the filter choice--even though I knew there were because I was searching in my own guild and had that item listed.
Once the bug shows up, the only way to get it to work again is to log out and log back in.