When you have Soul Cry activated on a Mystic Orc and make a trade, the trade will be cancelled automatically for no reason in a few seconds. Not sure if this bug is happening with other active skills.
Are you sure it's not the pick-up thing?
What pick up thing? I was in Orc Village to give some adena to my alt and I traded once, it got cancelled. I traded twice and it got odd. I traded third time and I saw that my Soul Cry skill is active, so that lead me to think that's the problem. I disabled it, traded again and waited 20s and my trade wasn't closing.
Bump
I guess you are right, my bad. I was in a party with my clan mate and he was farming, though he's in Talking Island and I think that's still a bug.. The trade shouldn't close when someone from the party picks in such a huge distance/radius.
When you are in a party and some other member picks up items, near you or at the other side of the map it doesn't matter, the trade window gets cancelled.