nope. not that. like back and forth like in a spot. like taht guild 2 bug where the cart is psinning but in this case left to right... :/
Viewing post in my wagon movers are going back and forth over and over.
Weird, that's the first I've heard of a bug like that.
If you deconstruct the tradehouse the wagons came from (through "Inspect" mode) the wagons should disband, and you'll get the people and pigs back. Saving and loading may also clear out any confusion in the AI.
Another possibility is that the wagons can't reach wherever they're going. Is the Trade Depo blocked off from them?