I found a map editor glitch. here is the video
https://www.mediafire.com/?qdiqkc3d7owrzr1

Yeah this isn't really a bug. The map editor is just a blue overlay over the default map which happens to be map 0, or your own map in case you validated it. Here is a related thread: click me

This has been always the case and it doesn't interfere with the gameplay or making maps. I wouldn't see what advantage would come from removing this :P