Mission Validation Problem

[i_b_spectre]

Thanks to BBW for providing an improved Mission Editor that fit within my display. I'm using Dietrich's ME User's Guide, but I've hit a snag. After placing ships, setting parameters, objectives, triggers and events, I run the mission validation check and get a list of error warnings. The first one says I have "Tramp Steamer #1 too close to Por Small Merchant #1 (current distance 211.9, minimum 300.0), yet using the radius ruler tool it measures 8.344 km. Also, I'm getting a list of 12 AI Tramp Steamers and 1 AI Medium Cargo ships that have "no waypoints attached". Thing is, there's only one Tramp Steamer and one Medium Cargo ship in the game and they both clearly have two waypoints. I've zoomed out to ensure an accidental mouse click could not have inadvertently placed objects elsewhere.

I've got a lot of experience building missions in IL-2 and Janes WW2F over the years, so while there are differences in some conventions, it's not apparent what's going on. Any ideas?