Ok. I give up. Here is another interesting "bug". I installed the dev 4.0 into a VANILLA copy of .20.2 (Into the GameData folder, as per all the instructions I have read in this thread). That solved the game-freezing issue, however, when I launch even the most basic ship into orbit to map, nothing shows up on them maps! The map screen remains blank. Hmmm. Guess I will just have to leave Mapsat alone until an actual working version comes out. especially if I can't use any other mods with it without the mapsat .dll wigging out.