Dave , on build 5.0.16 , just created a test map with no features other than a big blob of lake and a blob of woods. done the usual sequence to cache and save etc. When I select MAP-SHOW MOVEMENT FOR MOTORISED UNITS the lake shows impassable as is correct, the woods show passable . This happens for several repeats. When I look at maps from the core games and my own maps all seems fine though.