There was a huge (and stupid) rule change with the later editions, where if you run out of resource cards during a production phase, no one gets anything. Our group still plays the old way, where you parcel out that resource starting at the die roller, and going clockwise.

There was another smaller rule change that I don't remember right now, I'll edit it in when I get a chance to look it up.

There was a huge (and stupid) rule addition with the later editions, where if you run out of resource cards during a production phase, no one gets anything. In the old rules (1999, Mayfair) there was no rule on it, so our group always played where you parcel out that resource starting at the die roller, and going clockwise.

The new rules also allow you to move the robber to a desert hex, which was not allowed before.