It happens regardless of where I place the MDLviewer and regardless of the path's depth.
For instance, I put the viewer on D: and opened the same directory - no difference, some folders are always missed...

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt