The one where if your Settler(s)/Engineer(s) are clearing Forest and building Road, when the Forest clearing is finished and the Tile is Plains, building a Road still costs the same MP as Forest Road unless a turn is lost and Road building is then re-started anew. Also, the graphics get messed up when viewing the Units building the Road.
I think this happens whenever a Tile's terrain changes before multiple improvements finish. Either the rules need to say this is expected behavior and the graphics need to be fixed, or not.
Posted 12-Jan-10 00:40 by Cor'e =)