I know the quarries have been buggy, but I've noticed something with the sulfur quarry. I have put around 60k in fuel over the past couple of weeks and when I return there is nothing to pick up. Thing is, if I put fuel in and actually watch the output, sulfur will come out. I don't know if this is a matter of the sulfur quarry output messing up or that perhaps it may not be instanced and other players are able to access everything. (This is on EU Scourge)